Section outline

  • lesson content

    Timothy is planning a surprise birthday party for his sister at the local bowling alley. He has already arranged the food but wants to include bowling as an extra. The bowling alley has told Timothy that bowling shoes cost a flat rate of $2.00 and the cost to bowl is $3.00 per game. He has to figure out the cost for his sister and three friends to bowl and how many games they can bowl. Timothy only has $50.00 to spend on bowling. How can he figure out how many games they can bowl and have enough money to pay the total cost for four people?
    ::Timothy计划在当地保龄球馆为他妹妹举办生日派对。他已经安排了食物,但想将保龄球作为额外内容。保龄球馆告诉Timothy保龄球鞋的固定价格为2美元,保龄球费为每场比赛3美元。他必须弄清楚他妹妹和三个朋友打保龄球的费用以及他们能打多少场球。Timothy只能花50美元打保龄球。他如何知道他们可以打多少场保龄球,并有足够的钱支付四个人的总费用?

    In this concept, you will learn to evaluate function rules.
    ::在这一概念中,你将学会评价职能规则。

    Function Tables
    ::函数表

    A function is a relation such that each member of the domain is paired with one and only one member of the range . A set of ordered pairs ( x , y ) is a relation . The domain is the set of values made up of the x - coordinates of the ordered pairs while the range is the set of values made up of the y -values of the ordered pairs. A function table is an output/input table where the input value is a member of the domain and the output value is a member of the range. The output value is the result of an operation or operations performed on the input value and its value depends upon the input number.
    ::函数是一种关系, 使域中每个成员都配上一个且只有一个区域成员。 一组有顺序的对( x,y) 是关系。 域是由定对的x坐标组成的一组数值, 而范围是由定对的 y 值组成的一套数值。 函数表是一个输出/ 输入表, 输入值是域的一部分, 输出值是区域的一部分。 输出值是根据输入值进行的操作或操作的结果, 其值取决于输入数 。

    Look at the following function table:
    ::查看以下函数表:

    Input Output
    3 6
    4 8
    5 10
    6 12

    If ‘ x ’ represents the input value and ‘ y ’ represents the output value, the table can be used to write a function rule . A function rule is an expression written in either words or symbols to represent the operation or operations performed on the input number to give the output number. From the above table it is obvious that each output number ‘ y ’ is the result of doubling the input number ‘ x .’ The function rule written using symbols is the equation
    ::如果 " x " 表示输入值, "y " 表示输出值,则表格可用于写入函数规则。函数规则是用文字或符号写成的表达式,以表示在输入号上完成的操作或操作,以给出输出号。从上表可以明显看出,每个输出号 "y " 是输入号 "x " 翻一番的结果。 " 使用符号写入的函数规则是等式:

    y = 2 x

    ::y=2x y=2x

    Let’s apply a function rule to complete the following input/output table.
    ::让我们应用函数规则来完成以下输入/产出表 。

    Use the function rule y = 3 x + 2  to complete the table below.
    ::使用 y=3x+2 函数规则来填写下表。

    Input  ( x ) Output  "> ( y )
    2 8
    3 11
    4 14
    5 17

    First, substitute the input value of 2 into the function rule for the variable x .’
    ::首先,将 2 的输入值替换为变量 `x.' 的函数规则。

    y = 3 x + 2 y = 3 ( 2 ) + 2

    ::y=3x+2y=3(2)+2

    Next, perform the multiplication to clear the parenthesis.
    ::下一步,执行乘法清除括号。

    y = 3 ( 2 ) + 2 y = 6 + 2

    ::y=3(2)+2y=6+2

    Next, perform the addition on the right side of the equation.
    ::接下来,在方程右侧执行添加。

    y = 6 + 2 y = 8

    ::y=6+2y=8 y=8

    The answer is 8.
    ::答案是8岁

    The output value is 8 when the input value is 2.
    ::输入值为 2 时输出值为 8 。

    Then, write the output number in the table.
    ::然后,在表格中写出输出编号。

    Repeat the above process for each of the given input numbers.
    ::重复给定输入数字中的每个输入数字的上述进程 。

    x = 3 y = 3 x + 2 y = 3 ( 3 ) + 2 y = 9 + 2 y = 11

    ::x=3y=3x+2y=3(3)+2y=9+2y=11

    The answer is 11.
    ::答案是11个

    x = 4 y = 3 x + 2 y = 3 ( 4 ) + 2 y = 12 + 2 y = 14

    ::x=4y=3x+2y=3(4)+2y=12+2y=14

    The answer is 14.
    ::答案是14岁

    x = 5 y = 3 x + 2 y = 3 ( 5 ) + 2 y = 15 + 2 y = 17

    ::x=5y=3x+2y=3(5)+2y=15+2y=17

    The answer is 17.
    ::答案是17。

    Then, complete the table by filling in the calculated output numbers.
    ::然后填写计算出的产出数字,填写表格。

    Examples
    ::实例

    Example 1
    ::例1

    Earlier, you were given a problem about  Timothy and the surprise birthday party. 
    ::早些时候,你得到一个问题 关于提摩西 和惊喜生日派对。

    He needs to figure out how many games of bowling his sister and her friends can play for $50.00 or less. 
    ::他需要弄清楚 有多少打保龄球的游戏 他妹妹和她的朋友 可以玩50美元或更少。

    First, he must write a function rule to represent the information he has from the bowling alley.
    ::首先,他必须写一个功能规则 来代表他从保龄球馆得到的信息

    Shoes are a flat rate of $2.00 and each game played costs $3.00. The function rule for the information is: y = 3 x + 2  where ' y ' is the total cost and ' x ' is the number of games played.
    ::鞋子是2美元的统一费率,每场游戏费用为3.00美元。 信息功能规则是: y=3x+2, 其中“ Y” 是总成本, “ x” 是游戏次数。

    Next, create an input/output table.
    ::下一步,创建一个输入/产出表。

    Input  ( x ) Output  "> ( y )
    1 $5.00
    2 $8.00
    3 $11.00
    4 $14.00

    First, substitute the input value of 1 into the function rule for the variable ‘ x .’
    ::首先,将1的输入值替换为变量 'x' 的函数规则中的输入值。

    y = 3 x + 2 y = 3 ( 1 ) + 2

    ::y=3x+2y=3(1)+2

    Next, perform the multiplication to clear the parenthesis.
    ::下一步,执行乘法清除括号。

    y = 3 ( 1 ) + 2 y = 3 + 2

    ::y=3(1)+2y=3+2

    Next, perform the addition on the right side of the equation.
    ::接下来,在方程右侧执行添加。

    y = 3 + 2 y = 5

    ::y=3+2y=5 y=5 y=3+2y=5

    The answer is 5.
    ::答案是5。

    The output value is $5.00 for one person to bowl one game.
    ::输出值为5.00美元 一个人打一局

    Next, write the output number in the table.
    ::下一步,在表格中写出输出编号。

    Then, multiply $5.00 by 4 to determine the cost for four people to bowl one game.
    ::然后,乘以5.00乘以4 来决定四个人打一局的费用。

    $ 5.00 × 4 = $ 20.00

    The answer is $20.00.
    ::答案是$20.00。

    It will cost $20.00 for his sister and three friends to bowl one game.
    ::他妹妹和三个朋友打一局 需要20美元

    First, substitute the input value of 2 into the function rule for the variable ‘ x .’
    ::首先,将 2 的输入值替换为变量 `x.' 的函数规则。

    y = 3 x + 2 y = 3 ( 2 ) + 2

    ::y=3x+2y=3(2)+2

    Next, perform the multiplication to clear the parenthesis.
    ::下一步,执行乘法清除括号。

    y = 3 ( 2 ) + 2 y = 6 + 2

    ::y=3(2)+2y=6+2

    Next, perform the addition on the right side of the equation.
    ::接下来,在方程右侧执行添加。

    y = 6 + 2 y = 8

    ::y=6+2y=8 y=8

    The answer is 8.
    ::答案是8岁

    The output value is $8.00 for one person to bowl two games.
    ::输出值为8.00美元 一个人打两场球

    Next, write the output number in the table.
    ::下一步,在表格中写出输出编号。

    Then, multiply $8.00 by 4 to determine the cost for four people to bowl two games. 
    ::然后,乘以8.00乘以4 来决定四个人打两局的费用。

    $ 8.00 × 4 = $ 32.00

    The answer is $32.00.
    ::答案是32.00美元

    It will cost $32.00 for his sister and three friends to bowl two games.
    ::他妹妹和三个朋友打两场球要花32美元

    First, substitute the input value of 3 into the function rule for the variable ‘ x .’
    ::首先,将3的输入值替换为变量 'x' 的函数规则中的输入值。

    y = 3 x + 2 y = 3 ( 3 ) + 2

    ::y=3x+2y=3(3)+2

    Next, perform the multiplication to clear the parenthesis.
    ::下一步,执行乘法清除括号。

    y = 3 ( 3 ) + 2 y = 9 + 2

    ::y=3(3)+2y=9+2

    Next, perform the addition on the right side of the equation.
    ::接下来,在方程右侧执行添加。

    y = 9 + 2 y = 11

    ::y=9+2y=11 y=11

    The answer is 11.
    ::答案是11个

    The output value is $11.00 for one person to bowl three games.
    ::输出值是11美元 一个人打三局

    Next, write the output number in the table.
    ::下一步,在表格中写出输出编号。

    Then, multiply $11.00 by 4 to determine the cost for four people to bowl three games. 
    ::然后乘以11美元乘以4 确定四个人打三局的费用

    $ 11.00 × 4 = $ 44.00

    The answer is $44.00.
    ::答案是44.00美元

    It will cost $44.00 for his sister and three friends to bowl three games.
    ::他妹妹和三个朋友打三场球 要花44美元

    First, substitute the input value of 4 into the function rule for the variable ‘ x .’
    ::首先,将4的输入值替换为变量“x”的函数规则中的输入值。

    y = 3 x + 2 y = 3 ( 4 ) + 2

    ::y=3x+2y=3(4)+2

    Next, perform the multiplication to clear the parenthesis.
    ::下一步,执行乘法清除括号。

    y = 3 ( 4 ) + 2 y = 12 + 2

    ::y=3(4)+2y=12+2

    Next, perform the addition on the right side of the equation.
    ::接下来,在方程右侧执行添加。

    y = 12 + 2 y = 14

    ::y=12+2y=14

    The answer is 14.
    ::答案是14岁

    The output value is $14.00 for one person to bowl four games.
    ::输出值是14.00美元 一个人打四场球

    Next, write the output number in the table.
    ::下一步,在表格中写出输出编号。

    Then, multiply $14.00 by 4 to determine the cost for four people to bowl four games. 
    ::然后,乘以14美元乘以4 来决定四个人打四场球的费用。

    $ 14.00 × 4 = $ 56.00

    The answer is $56.00.
    ::答案是56.00美元

    It will cost $56.00 for his sister and three friends to bowl four games.
    ::他妹妹和三个朋友打四场球要花56美元

    Timothy has enough money for his sister and three friends to bowl three games.
    ::Timothy有足够的钱 供他妹妹和三个朋友打三场球

    Examples 2
    ::实例2

    Use the following function rule to complete the input/output table.
    ::使用以下函数规则完成输入/产出表。

    y = 2 x 5

    ::y=2x-5

    Input  ( x ) Output  "> ( y )
    -5 -15
    -1 -7
    2 -1
    6 7

    First, substitute the input value of -5 into the function rule for the variable ‘ x .’
    ::首先,将 -5 的输入值替换为变量 `x.' 的函数规则。

    y = 2 x 5 y = 2 ( 5 ) 5

    ::y=2x-5y=2-5-5-5-5

    Next, perform the multiplication to clear the parenthesis.
    ::下一步,执行乘法清除括号。

    y = 2 ( 5 ) 5 y = 10 5

    ::y=2 (-5) - 5y 10 - 5

    Next, perform the addition of the two negative values on the right side of the equation.
    ::下一步,在方程式右侧添加两个负值。

    y = 10 5 y = 15

    ::y 10 - 5y 15

    The answer is -15.
    ::答案是 -15

    The output value is -15 when the input value is -5.
    ::当输入值为 - 5 时输出值为 - 15。

    Then, write the output number in the table.
    ::然后,在表格中写出输出编号。

    Repeat the above process for each of the given input numbers.
    ::重复给定输入数字中的每个输入数字的上述进程 。

    x = 1 y = 2 x 5 y = 2 ( 1 ) 5 y = 2 5 y = 7

    ::x1y=2x-5y=2(-1)-5y=2-5y}2-5y=7

    The answer is -7.
    ::答案是 -7

    x = 2 y = 2 x 5 y = 2 ( 2 ) 5 y = 4 5 y = 1

    ::x=2y=2x-5y=2(2)-5y=4-5y=5y=1

    The answer is -1.
    ::答案是 -1

    x = 6 y = 2 x 5 y = 2 ( 6 ) 5 y = 12 5 y = 7

    ::x=6y=2x-5y=2(6)-5y=12-5y=7

    The answer is 7.
    ::答案是7个

    Example 3
    ::例3

    Use the given function rule to complete the input/output table: 
    ::使用给定函数规则完成输入/产出表 :

    y = 4 x 3

    ::y=4x-3 y=4x-3

    Input  ( x ) Output  "> ( y )
    4 13
    5 17
    7 25
    9 33

    First, substitute the input value of 4 into the function rule for the variable ‘ x .’
    ::首先,将4的输入值替换为变量“x”的函数规则中的输入值。

    y = 4 x 3 y = 4 ( 4 ) 3

    ::y=4x-3y=4(4)-3

    Next, perform the multiplication to clear the parenthesis.
    ::下一步,执行乘法清除括号。

    y = 4 ( 4 ) 3 y = 16 3

    ::y=4(4)-3y=16-3

    Next, perform the subtraction on the right side of the equation.
    ::下一步,在方程右侧执行减法。

    y = 16 3 y = 13

    ::y=16 - 3y=13

    The answer is 13.
    ::答案是13岁

    The output value is 13 when the input value is 4.
    ::输入值为 4 时输出值为 13。

    Then, write the output number in the table.
    ::然后,在表格中写出输出编号。

    Repeat the above process for each of the given input numbers.
    ::重复给定输入数字中的每个输入数字的上述进程 。

    x = 5 y = 4 x 3 y = 4 ( 5 ) 3 y = 20 3 y = 17

    ::x=5y=4x-3y=4(5)-3y=20-3y=17

    The answer is 17.
    ::答案是17。

    x = 7 y = 4 x 3 y = 4 ( 7 ) 3 y = 28 3 y = 25

    ::x7y=4x-3y=4(7)-3y=28-3y=25

    The answer is 25.
    ::答案是25岁

    x = 9 y = 4 x 3 y = 4 ( 9 ) 3 y = 36 3 y = 33

    ::x9y=4x-3y=4(9)-3y=36-3y=33

    The answer is 33.
    ::答案是33岁

    Example 4
    ::例4

    Use the given function rule to complete the input/output table: 
    ::使用给定函数规则完成输入/产出表 :

    y = 2 x + 7

    ::y2x+7 y2x+7

    Input  ( x ) Output  "> ( y )
    -14 35
    -9 25
    4 -1
    11 -15

    First, substitute the input value of -14 into the function rule for the variable ‘ x .’
    ::首先,将 -14 的输入值替换为变量 `x.' 的函数规则。

    y = 2 x + 7 y = 2 ( 14 ) + 7

    ::y2x+7y=2( - 14)+7

    Next, perform the multiplication to clear the parenthesis.
    ::下一步,执行乘法清除括号。

    y = 2 ( 14 ) + 7 y = 28 + 7

    ::y2( - 14)+7y=28+7

    Next, perform the addition on the right side of the equation.
    ::接下来,在方程右侧执行添加。

    y = 28 + 7 y = 35

    ::y=28+7y=35

    The answer is 35.
    ::答案是35岁

    The output value is 35 when the input value is -14.
    ::当输入值为 -14 时输出值为 35 。

    Then, write the output number in the table.
    ::然后,在表格中写出输出编号。

    Repeat the above process for each of the given input numbers.
    ::重复给定输入数字中的每个输入数字的上述进程 。

    x = 9 y = 2 x + 7 y = 2 ( 9 ) + 7 y = 18 + 7 y = 25

    ::x9y2x+7y2(- 9)+7y=18+7y=25

    The answer is 25.
    ::答案是25岁

    x = 4 y = 2 x + 7 y = 2 ( 4 ) + 7 y = 8 + 7 y = 1

    ::x=4y2x+7y2(4)+7y8+7y1

    The answer is -1.
    ::答案是 -1

    x = 11 y = 2 x + 7 y = 2 ( 11 ) + 7 y = 22 + 7 y = 15

    ::x=11y2x+7y2(11)+7y22+7y15

    The answer is -15.
    ::答案是 -15

    Example 5
    ::例5

    Use the given function rule to complete the input/output table:
    ::使用给定函数规则完成输入/产出表 :

    y = 3 x 14

    ::y=3x- 14 y

    Input  ( x ) Output  "> ( y )
    -10 -44
    -7 -35
    2 -8
    9 13

    First, substitute the input value of -10 into the function rule for the variable ‘ x .’
    ::首先,将 - 10 的输入值替换为变量 `x.' 的函数规则。

    y = 3 x 14 y = 3 ( 10 ) 14

    ::y=3x- 14y=3(- 10)- 14

    Next, perform the multiplication to clear the parenthesis.
    ::下一步,执行乘法清除括号。

    y = 3 ( 10 ) 14 y = 30 14

    ::y=3 (- 10)- 14y30- 14

    Next, perform the addition on the right side of the equation.
    ::接下来,在方程右侧执行添加。

    y = 30 14 y = 44

    ::y30 - 14y44

    The answer is -44.
    ::答案是 -44

    The output value is -44 when the input value is -10.
    ::当输入值为 - 10 时,输出值为 - 44。

    Then, write the output number in the table.
    ::然后,在表格中写出输出编号。

    Repeat the above process for each of the given input numbers.
    ::重复给定输入数字中的每个输入数字的上述进程 。

    x = 7 y = 3 x 14 y = 3 ( 7 ) 14 y = 21 14 y = 35

    ::x7y= 3x- 14y= 3(-7)- 14y_ 21- 14y_ 35

    The answer is -35.
    ::答案是 -35

    x = 2 y = 3 x 14 y = 3 ( 2 ) 14 y = 6 14 y = 8

    ::x=2y=3x-14y=3(2)-14y=6-14y=8

    The answer is -8.
    ::答案是 -8

    x = 9 y = 3 x 14 y = 3 ( 9 ) 14 y = 27 14 y = 13

    ::x=9y=3x-14y=3(9)-14y=27-14y=13

    The answer is 13.
    ::答案是13岁

    Review
    ::回顾

    For numbers 1-5, find each output if the function rule is y = 3 x + 2 .
    ::对于数字1-5,如果函数规则为y=3x+2,请查找每项输出。

    Problem Number Input Output
    1. 3  
    2. 5  
    3. 6  
    4. 9  
    5. 11  

    For numbers 6-10, find each output if the function rule is y = 4 x .
    ::对于数字 6-10, 如果函数规则为y=4x, 请查找每项输出 。

    Problem Number Input Output
    6. -3  
    7. -4  
    8. 0  
    9. 1  
    10. 2  

    For numbers 11-15, find each output if the function rule is y = 3 x .
    ::对于数字11-15, 如果函数规则为 y3x, 则查找每项输出 。

    Problem Number Input Output
    11. 4  
    12. 5  
    13. 7  
    14. 9  
    15. 10  

    Answer each question about functions.
    ::回答每个关于职能的问题。

    16. A pastry chef needs to purchase enough dough for her cookies. She buys one pound of dough for every twenty cookies she is going to make. She uses the function C ( d ) = 20 d  where C is the number of cookies and d  is the pounds of dough she should buy. Identify which variable is the domain and which is the range.
    ::16. 一位糕点厨师需要为她的饼干购买足够的面粉,她每要做20个饼干就买一磅面粉,她使用C(d)=20d函数,C是饼干的数量,D是她应该买的面粉的重量。她确定哪个变量是域,哪个是范围。

    17. Evaluate the function f ( x ) = 2 x + 7  when the domain is { 3 , 1 , 1 , 3 } .
    ::17. 当域为%3, - 1,1,1,3}时评价函数 f(x)=2x+7。

    18. Evaluate the function f ( x ) = 2 5 x 6  when the domain is { 10 , 5 , 0 , 5 , 10 } .
    ::18. 当域为%10,-5,0,5,10}时评价函数 f(x)=25x-6。

    19. Evaluate the function f ( x ) = 3 x 1  when the domain is { 5 , 6 , 7 , 8 , 9 } .
    ::19. 当域为{5,6,7,7,8,9}时评价函数 f(x)=3x-1。

    20. Evaluate the function f ( x ) = x 9  when the domain is { 1 , 2 , 3 , 4 , 5 } .
    ::20. 当域为{1,2,3,4,5}时评价函数 f(x)=x-9。

    Review (Answers)
    ::回顾(答复)

    Click to see the answer key or go to the Table of Contents and click on the Answer Key under the 'Other Versions' option.
    ::单击可查看答题键, 或转到目录中, 单击“ 其他版本” 选项下的答题键 。