Section outline

  • The area of a rectangle is 6 x 3 12 x 2 + 4 x 8 . The width of the rectangle is 2 x 4 . What is the length?
    ::矩形区域为 6x3 - 12x2+4x- 8. 矩形宽度为 2x-4。 长度是多少?

    Long Division of Polynomials
    ::长长的多配偶分会

    Even though it does not seem like it, factoring is a form of division . Each factor goes into the larger polynomial evenly, without a remainder.
    ::尽管似乎并不像,但保理是一种划分形式。 每一个因素均匀地进入更大的多元性,没有剩余部分。

    For example, take the polynomial 2 x 3 3 x 2 8 x + 12 . If we use factoring by grouping , we find that the factors are ( 2 x 3 ) ( x 2 ) ( x + 2 ) . If we multiply these three factors together, we will get the original polynomial. So, if we divide by 2 x 3 , we should get x 2 4.
    ::例如,采用多数值 2x3-3x2- 3x2-8x+12。如果我们按分组使用乘数,我们发现系数是 2x-3 (x-2)(x+2) 。如果我们将这三个系数乘在一起,我们就会得到原始的多数值。所以,如果我们除以 2x-3,我们就应该得到 x2- 4 。

    2 x 3 2 x 3 3 x 2 8 x + 12

    ::2 - 32x3 - 3x2 - 8x+12

    How many times does 2 x go into 2 x 3 ?  Since 2 x ( x 2 ) = 2 x 3 ,  it goes in  x 2 times.
    ::自 2x( x2) = 2x3 以x2 乘以 。

    x 2 00000000000000 2 x 3 2 x 3 3 x 2 8 x + 12 2 x 3 3 x 2 _ 000000000 0 0000000000

    ::x2000000000002x - 32x3 - 3x2 - 8x+122x3 - 3x2 - 00000000000000000

    Place x 2 above the x 2 term in the polynomial.
    ::将 x2 移动到多义中的 x2 术语之上 。

    Multiply x 2 by both terms in the divisor ( 2 x and -3) and place them under their like terms . Subtract from the dividend ( 2 x 3 3 x 2 8 x + 12 ) .  Pull down the next two terms and repeat.
    ::乘以乘数2, 在 divisor ( 2x 和 3) 中用两个词来表示, 并将其置于相同的条件之下 。 从股息( 2x3-3x2 - 8x2 - 8x+12) 中扣除 。

    x 2 00000 4 00000 2 x 3 2 x 3 3 x 2 8 x + 12 2 x 3 3 x 2 00 _ 8 x + 12 8 x + 12 _

    ::x200000-4000002x-32-3x3-3x2-8x+122x3-3x200__BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_BAR_三三三三三三三三三三三x_三三三三三三三三x_三x_三x_三x_一__八_

    Since  2 x ( - 4 ) = - 8 x , 2 x  goes into 8 x  a total of -4 times.
    ::自2x( 4) = 8x 2x 进入- 8x 共 - 4 次。

    After multiplying both terms in the divisor by -4, place that under the terms you brought down. When subtracting, notice that everything cancels out. Therefore  x 2 4 is indeed a factor.
    ::在将两个条件乘以 4 后, 将两个条件乘以 4 后, 将您下调的条件置于您下调的条件之下 。 减去时, 通知所有条件都取消 。 因此 x2 - 4 确实是一个因素 。

    When , not every divisor will go in evenly to the dividend. If there is a remainder, write it as a fraction over the divisor.
    ::当不是每个小提琴家都能平均进入股息时。如果还有剩余部分,请将其写成比小的分数在小提琴上方。

    Divide using long division:  ( 2 x 3 6 x 2 + 5 x 20 ) ÷ ( x 2 5 )
    ::使用长除法除法的除法 : (2x3- 6x2+5x- 20) (x2- 5)

    Set up the problem using a long division bar.
    ::使用长分隔栏设置问题 。

    x 2 5 2 x 3 6 x 2 + 5 x 20

    ::x2 - 52x3 - 6x2+5x-20

    How many times does x 2 go into 2 x 3 ?  Since x 2 ( 2 x ) = 2 x 3 ,  it goes in  2 x times.
    ::x2 进入 2x3 多少次? 从 x2( 2x) = 2x3 开始, 它以 2x 倍 。

    2 x 00000000000000 x 2 5 2 x 3 6 x 2 + 5 x 20 2 x 3 10 x 2 0 _ 4 x 2 + 5 x 20

    ::2x000000000x2 - 52x3 - 6x2+5x - 202x3 - 10x20 - 4x2+5x-20

    Multiply 2 x by the divisor. Subtract that from the dividend.
    ::乘以乘以二乘法 减去股息

    Repeat the previous steps. Now, how many times does x 2 go into 4 x 2 ? It goes in 4 times.
    ::重复前几步。 现在, x2 进入 4x2 多少次? 它使用 4 次 。

    2 x 00 + 4 000000000 x 2 5 2 x 3 6 x 2 + 5 x 20 2 x 3 10 x 2 0 _ 4 x 2 + 5 x 20 4 x 2 0000 20 _ 5 x 00

    ::2x00+400000000x2-52x3-6x2+5x-202+5x20x3-10x20_4x2+5x-204x20000-20_5x00

    This is the limit of this process . x 2 cannot go evenly into 5 x because it has a higher degree . Therefore , 5 x is a remainder. The complete answer would be 2 x + 4 + 5 x x 2 5 .
    ::这是这个过程的极限。 x2 无法平均进入 5x, 因为它具有更高的学位。 因此, 5x 是剩余部分。 完整答案是 2x+4+5x2-5 。

    Divide using long division: ( 3 x 4 + x 3 17 x 2 + 19 x 6 ) ÷ ( x 2 2 x + 1 )
    ::使用长除法除法除法 : (3x4+x3- 17x2+19x- 6) (x2-2x+1)

    Determine if x 2 2 x + 1 goes evenly into 3 x 4 + x 3 17 x 2 + 19 x 6 . If so, try to factor the divisor and quotient further.
    ::确定 x2 - 2x+1 是否均匀地切入 3x4+x3 - 17x2+19x-6。 如果是的话, 请尝试进一步乘以差数和商数 。

    First, do the long division. If x 2 2 x + 1 goes in evenly, then the remainder will be zero.
    ::首先, 执行长的分隔。 如果 x2-2x+1 平均进入, 那么剩下的将是零 。

    3 x 2 + 7 x 000 6 000000000 x 2 2 x + 1 3 x 4 + x 3 17 x 2 + 19 x 6 3 x 4 6 x 3 00 3 x 2 000000000 _ 7 x 3 20 x 2 + 19 x 000 7 x 3 14 x 2 + 0 7 x 000 _ 6 x 2 + 12 x 6 6 x 2 + 12 x 6 _ 0

    ::3x2+7x000 - 6000000000000x2 - 60000000x2 - 60000000000x2 - 2x+13x4+x3-17x2+19x63x4 - 6x2 - 6x3003x2000000 - 7x3 - 20x3 - 7x3 - 20x2+19x0007x3 - 14x2+07x000*_6x2+12x-6-6x2+12x6_0

    This means that x 2 2 x + 1 and 3 x 2 + 7 x 6 both go evenly into 3 x 4 + x 3 17 x 2 + 19 x 6 . Let’s see if we can factor either x 2 2 x + 1 or 3 x 2 + 7 x 6 further.
    ::这意味着 x2 - 2x+1 和 3x2+7x-6 均匀地进入 3x4+x3 - 17x2+19x-6 。让我们看看能不能进一步乘以 x2 - 2x+1 或 3x2+7x-6 。

    x 2 2 x + 1 = ( x 1 ) ( x 1 ) and 3 x 2 + 7 x 6 = ( 3 x 2 ) ( x + 3 ) .
    ::x2-2x+1=(x-1)(x-1)和3x2+7x-6=(3x-2)(x+3)。

    Therefore, 3 x 4 + x 3 17 x 2 + 19 x 6 = ( x 1 ) ( x 1 ) ( x + 3 ) ( 3 x 2 ) .  You can multiply these to check the work. A binomial with a degree of one is a factor of a larger polynomial  f ( x ) ,  if it goes evenly into it. In this problem , ( x 1 ) ( x 1 ) ( x + 3 ) and ( 3 x 2 ) are all factors of 3 x 4 + x 3 17 x 2 + 19 x 6 . This indicates that  1, 1, -3, and 2 3 are all solutions of 3 x 4 + x 3 17 x 2 + 19 x 6.
    ::因此, 3x4+x3- 17x2+19x-6=(x-1)(x-1)(x-1)(x- 1)(x+3)(3x-2) 。您可以乘以这些来检查工作。 具有一度的二进制是较大多圆性f(x) 的一个系数, 如果它处于均匀状态的话。 在此问题上, (x-1)(x-1)(x-1)(x+3)(x+3) 和(3x-2) 3x4+x3- 17x2+19x-6) 的所有系数都是 3x4+x3- 172+19x-6。 这表明, 1, 1, 3, 3 +x3- 3- 17x2+19x-6 的所有解决方案都是 3x4+x3- 17x2+19x-6 。

    Factor Theorem : A polynomial, f ( x ) , has a factor, ( x k ) , if and only if f ( k ) = 0 .
    ::系数定理: 多式, f(x), 有系数, (x-k) , 如果且仅在 f(k) =0 的情况下。

    In other words, if k is a solution or a zero , then the factor, ( x k ) divides evenly into f ( x ) .
    ::换句话说,如果 k是溶液或零,则系数(x-k)平均分为f(x)。

    Now, let's determine if 5 is a solution of x 3 + 6 x 2 8 x + 15 .
    ::现在,让我们来决定 5 是否是 x3+6x2 - 8x+15 的解决方案 。

    To see if 5 is a solution, we need to divide the factor into x 3 + 6 x 2 8 x + 15 . The factor that corresponds with 5 is ( x 5 ) .
    ::要想确定 5 是否是一个解决方案,我们需要将系数除以 x3+6x2-8x+15。 对应于 5 的系数是 (x-5) 。

    x 2 + 11 x 0 + 5 00000 x 5 x 3 + 6 x 2 50 x + 15 x 3 0 5 x 2 000000000 _ 11 x 2 0 50 x 0000 11 x 2 0 55 x 0000 _ 5 x + 15 5 x 25 _ 40

    ::x2+11x0+500000x-5x3+6x2-50x+15x3-05x2000000_11x2-050x000011x2-055x0000_5x+155x-25_40

    Since there is a remainder, 5 is not a solution.
    ::由于还有剩余部分,5项不是解决办法。

    Examples
    ::实例

    Example 1
    ::例1

    Earlier, you were asked to find  the length of the rectangle. 
    ::早些时候,有人要求你找到矩形的长度。

    First, do the long division.
    ::首先,做长期的划分。

    3 x 2 0000000 + 2 0000 2 x 4 6 x 3 12 x 2 + 4 x 8 6 x 3 12 x 2 0 _ 4 x 8 4 x 8 _ 0

    ::3x2000000+200002x-46x3-12x2+4x-86x3-12x20_4x-84x-8_0

    This means that 2 x 4 and 3 x 2 + 2 both go evenly into 6 x 3 12 x 2 + 4 x 8 .
    ::这意味着 2x-4 和 3x2+2 均匀地进入 6x3 - 12x2+4x-8。

    3 x 2 + 2 can't be factored further, so it is the rectangle's length.
    ::3x2+2 无法进一步计算, 所以它是矩形的长度 。

    Example 2
    ::例2

    Divide:  ( 5 x 4 + 6 x 3 12 x 2 3 ) ÷ ( x 2 + 3 ) .
    ::除法: (5x4+6x3- 12x2-3) (x2+3)。

     Make sure to put a placeholder in for the x term.
    ::确保 x- term 设置一个占位符 。

    5 x 2 + 6 x 00 27 000000000 x 2 + 3 5 x 4 + 6 x 3 12 x 2 + 0 x 3 5 x 4 00000 + 15 x 2 00000000 _ 6 x 3 27 x 2 + 0 x 0 6 x 3 000 + 18 x 000 _ 27 x 2 18 x 3 27 x 2 00 81 _ 18 x + 78

    ::5x2+6x00- 27000000000x2+354x4+6x3- 12x2+0x3-6x3- 12x2+0x3- 4x6x4- 40000+15x2000000_ 6x3- 15x200000_ 6x3- 27x2+0x2+0x0x3000+18x000_ 272_ 18x_ 3- 27x_ 18x_ 81_18x+78

    The final answer is 5 x 2 + 6 x 27 18 x 78 x 2 + 3 .
    ::最后一个答案是5x2+6x-27-18x-78x2+3。

    Example 3
    ::例3

    Is ( x + 4 ) a factor of x 3 2 x 2 51 x 108 ? If so, find any other factors.
    :sadx+4) 是 x3-2x2-51x-108的因数吗?如果是的话,请找到任何其他因数。

    Divide ( x + 4 ) into x 3 2 x 2 51 x 108 and if the remainder is zero, it is a factor.
    ::将(x+4)除以x3-2x2-51x-108,如果其余为零,则是一个系数。

    x 2 6 x 27 0000000 x + 4 x 3 2 x 2 51 x 108 x 3 + 4 x 2 00000000000 _ 6 x 2 51 x 000000 6 x 2 24 x 000000 _ 27 x 108 27 x 108 _ 0

    ::x2 - 6x - 270000000x+4x3 - 2x2 - 51x - 108x3+4x2000000000 *6x2 - 51x000000 - 6x2 - 24x000 *27x - 108 - 27x - 108_ 0

    x + 4 is a factor. Let’s see if x 2 6 x 27 factors further. Yes, the factors of -27 that add up to -6 are -9 and 3. Therefore, the factors of x 3 2 x 2 51 x 108 are ( x + 4 ) , ( x 9 ) , and ( x + 3 ) .
    ::x+4 是一个因素。 让我们看看 x2 - 6x - 27 因素是否进一步。 是的, 27 因素加到 - 6 是 - 9 和 3 。 因此, x3 - 2x2 - 51x- 108 因素是 (x+4) 、 (x- 9) 和 (x+3) 。

    Example 4
    ::例4

    What are the real-number solutions to Example 3?
    ::例3的实际数字解决办法是什么?

    The solutions would be -4, 9, and 3; the opposite sign of each factor.
    ::解决办法是4、9和3;每个因素的相反标志。

    Example 5
    ::例5

    Determine if 6 is a solution to 2 x 3 9 x 2 12 x 24 .
    ::确定 6 是 2x3- 9x2- 12x- 24 的解决方案 。

    To see if 6 is a solution, we need to divide ( x 6 ) into 2 x 3 9 x 2 12 x 24 .
    ::看看6是否是一种解决办法,我们需要将(x-6)分为2x3-9x2-12x-24。

    2 x 2 + 3 x 0 + 6 0 00000 x 6 2 x 3 9 x 2 12 x 24 2 x 3 12 x 2 000000000 _ 3 x 2 12 x 0000 3 x 2 18 x 0000 _ 6 x 24 6 x 36 _ 12

    ::2x2+3x0+600000x-62x3-9x2-12x-242x3-12x12x2000000_3x2-12x2-12x0003x2-12x0003x2-18x0003x2-18x00_6x-246x-36_12

    Because the remainder is not zero, 6 is not a solution.
    ::因为其余部分不是零,6项不是解决办法。

    Review
    ::回顾

    Divide the following polynomials using long division.
    ::使用长除法除以下列多数值。

    1. ( 2 x 3 + 5 x 2 7 x 6 ) ÷ ( x + 1 )
      :sad2x3+5x2-7x-6)(x+1)
    2. ( x 4 10 x 3 + 15 x 30 ) ÷ ( x 5 )
      :sadx4-10x3+15x-30) (x-5)
    3. ( 2 x 4 8 x 3 + 4 x 2 11 x 1 ) ÷ ( x 2 1 )
      :sad2x4-8x3+4x2-11x-1)(x2-1)
    4. ( 3 x 3 4 x 2 + 5 x 2 ) ÷ ( 3 x + 2 )
      :sad3x3-4x2+5x-2)(3x+2)
    5. ( 3 x 4 5 x 3 21 x 2 30 x + 8 ) ÷ ( x 4 )
      :sad3x4-5x3-21x2-30x+8)(x-4)
    6. ( 2 x 5 5 x 3 + 6 x 2 15 x + 20 ) ÷ ( 2 x 2 + 3 )
      :sad2x5-5x3+6x2-15x+20)(2x2+3)

    Determine all the real-number solutions to the following polynomials, given one factor.
    ::确定以下多边数的所有真实数字解决方案, 给一个系数 。

    1. x 3 9 x 2 + 27 x 15 ; ( x + 5 )
      ::x3- 9x2+27x-15; (x+5)
    2. x 3 + 4 x 2 9 x 36 ; ( x + 4 )
      ::x3+4x2-9x-36; (x+4)
    3. 2 x 3 + 7 x 2 7 x 30 ; ( x 2 )
      ::2x3+7x2-7x2-7x-30; (x-2)

    Determine all the real number solutions to the following polynomials, given one zero.
    ::确定以下多边数的所有真实数字解决方案, 给以 零 。

    1. 6 x 3 37 x 2 + 5 x + 6 ; 6
      ::6x3-3-37x2+5x6;6
    2. 6 x 3 41 x 2 + 58 x 15 ; 5
      ::6x3-41x2+58x-15;5
    3. x 3 + x 2 16 x 16 ; 4
      ::x3+x2-16x-16;4

    Find the equation of a polynomial with the given zeros.
    ::查找给定零的多元分子方程式的方程式。

    1. 4, -2, and 3 2
      ::4,2-2和32
    2. 1, 0, and 3
      ::1, 0, 和 3
    3. -5, -1, and 3 4
      ::5、5-1和34
    4. Challenge Find two polynomials with the zeros 8, 5, 1, and -1.
      ::挑战发现两个多面体 零点8,5,1和1

    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 。