6.9 长期多民族分会
Section outline
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The area of a rectangle is . The width of the rectangle is . 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 . If we use factoring by grouping , we find that the factors are . If we multiply these three factors together, we will get the original polynomial. So, if we divide by , we should get
::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 - 32x3 - 3x2 - 8x+12How many times does go into Since it goes in times.
::自 2x( x2) = 2x3 以x2 乘以 。
::x2000000000002x - 32x3 - 3x2 - 8x+122x3 - 3x2 - 00000000000000000Place above the term in the polynomial.
::将 x2 移动到多义中的 x2 术语之上 。Multiply by both terms in the divisor ( and -3) and place them under their like terms . Subtract from the dividend 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 。
::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 goes into 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 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:
::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 。
::x2 - 52x3 - 6x2+5x-20How many times does go into Since it goes in times.
::x2 进入 2x3 多少次? 从 x2( 2x) = 2x3 开始, 它以 2x 倍 。
::2x000000000x2 - 52x3 - 6x2+5x - 202x3 - 10x20 - 4x2+5x-20Multiply 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 go into ? It goes in 4 times.
::重复前几步。 现在, x2 进入 4x2 多少次? 它使用 4 次 。
::2x00+400000000x2-52x3-6x2+5x-202+5x20x3-10x20_4x2+5x-204x20000-20_5x00This is the limit of this process . cannot go evenly into because it has a higher degree . Therefore , is a remainder. The complete answer would be
::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:
::使用长除法除法除法 : (3x4+x3- 17x2+19x- 6) (x2-2x+1)Determine if goes evenly into . 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 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 。
::3x2+7x000 - 6000000000000x2 - 60000000x2 - 60000000000x2 - 2x+13x4+x3-17x2+19x63x4 - 6x2 - 6x3003x2000000 - 7x3 - 20x3 - 7x3 - 20x2+19x0007x3 - 14x2+07x000*_6x2+12x-6-6x2+12x6_0This means that and both go evenly into . Let’s see if we can factor either or 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 。and .
::x2-2x+1=(x-1)(x-1)和3x2+7x-6=(3x-2)(x+3)。Therefore, You can multiply these to check the work. A binomial with a degree of one is a factor of a larger polynomial if it goes evenly into it. In this problem , and are all factors of . This indicates that 1, 1, -3, and are all solutions of
::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, , has a factor, , if and only if .
::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 is a solution or a zero , then the factor, divides evenly into .
::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 .
::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 . The factor that corresponds with 5 is .
::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) 。
::x2+11x0+500000x-5x3+6x2-50x+15x3-05x2000000_11x2-050x000011x2-055x0000_5x+155x-25_40Since 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1Earlier, 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。
::3x2000000+200002x-46x3-12x2+4x-86x3-12x20_4x-84x-8_0This means that and both go evenly into .
::这意味着 2x-4 和 3x2+2 均匀地进入 6x3 - 12x2+4x-8。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2Divide: .
::除法: (5x4+6x3- 12x2-3) (x2+3)。Make sure to put a placeholder in for the term.
::确保 x- term 设置一个占位符 。
::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+78The final answer is .
::最后一个答案是5x2+6x-27-18x-78x2+3。Example 3
::例3Is a factor of ? If so, find any other factors.
:x+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 into 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。
::x2 - 6x - 270000000x+4x3 - 2x2 - 51x - 108x3+4x2000000000 *6x2 - 51x000000 - 6x2 - 24x000 *27x - 108 - 27x - 108_ 0is a factor. Let’s see if factors further. Yes, the factors of -27 that add up to -6 are -9 and 3. Therefore, the factors of are , and .
::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4What 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5Determine if 6 is a solution to .
::确定 6 是 2x3- 9x2- 12x- 24 的解决方案 。To see if 6 is a solution, we need to divide into .
::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。
::2x2+3x0+600000x-62x3-9x2-12x-242x3-12x12x2000000_3x2-12x2-12x0003x2-12x0003x2-18x0003x2-18x00_6x-246x-36_12Because 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。-
:2x3+5x2-7x-6)(x+1)
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:x4-10x3+15x-30) (x-5)
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:2x4-8x3+4x2-11x-1)(x2-1)
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:3x3-4x2+5x-2)(3x+2)
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:3x4-5x3-21x2-30x+8)(x-4)
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:2x5-5x3+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 。-
::x3- 9x2+27x-15; (x+5) -
::x3+4x2-9x-36; (x+4) -
::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 。-
::6x3-3-37x2+5x6;6 -
::6x3-41x2+58x-15;5 -
::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。-
4, -2, and
::4,2-2和32 -
1, 0, and 3
::1, 0, 和 3 -
-5, -1, and
::5、5-1和34 -
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 。 -