因式分解技巧
虽然读书那会都没认真把这套书做掉,但现在既然有机会,就趁此回过头了再稍微认真的给自己复习一遍,就当是重新打牢基础了吧。
习题1(更新于2025年05月08日)
将以下各式分解因式:
- $5x^2y-10xyz+5xy$
解:$$\text{原式}= 5xy(x-2z+1)$$
- $a(x-a)+b(a-x)-(x-a)$
解:$$\text{原式}= (x-a)(a-b-1)$$
- $-2x(x+1)+a(x+1)+(x+1)$
解:$$\text{原式}= (x+1)(-2x+a+1)$$
- $\frac{3}{2}b^{3n-1}+\frac{1}{6}b^{2n-1}$
解: $$ \begin{aligned} \text{原式}&=\frac{1}{6}(9b^{3n-1}+b^{2n-1}) \\ &=\frac{1}{6}b^{2n-1}(9b^n+1) \end{aligned} $$
- $2(p-1)^2-4q(p-1)$
解: $$ \begin{aligned} \text{原式}&=(p-1)(2(p-1)-4q) \\ &=(p-1)(2p-2-4q) \end{aligned} $$
- $mn(m^2+n^2)-n^2(m^2+n^2)$
解:$$\text{原式}=(mn-n^2)(m^2+n^2)$$
- $(5a-2b)(2m+3p)-(2a-7p)(2m+3p)$
解: $$ \begin{aligned} \text{原式}&=(2m+3p)(5a-2b-(2a-7p)) \\ &=(2m+3p)(3a-2b+7p) \end{aligned} $$
- $2(x+y)+6(x+y)^2-4(x+y)^3$
解: $$ \begin{aligned} \text{原式}&=(x+y)(2+6(x+y)-4(x+y)^2) \\ &=(x+y)(2+6x+6y-4x^2-8xy-4y^2) \end{aligned} $$
- $(x+y)^2(b+c)-(x+y)(b+c)^2$
解: $$ \begin{aligned} \text{原式}&=(x+y)(b+c)((x+y)-(b+c)) \\ &=(x+y)(b+c)(x+y-b-c) \end{aligned} $$
- $6p(x-1)^3-8p^2(x-1)^2-2p(1-x)^2$
解: $$ \begin{aligned} \text{原式}&=2p(x-1)^{2}(3(x-1)-4p-1) \\ &=2p(x-1)^2(3x-4p-4) \end{aligned} $$
习题2(更新于2025年05月08日)
将以下各式分解因式:
- $16-(3a+2b)^2$
解: $$ \begin{aligned} \text{原式}&=(4+(3a+2b))(4-(3a+2b)) \\ &=(4+3a+2b)(4-3a-2b) \end{aligned} $$