第72页 - 经纶学典学霸七年级数学上下册【江苏国标】

D

A

C

x(y+2)(y-2)

x(x-3)²

-a(a-1)²

3(a²+b²)(a+b)(a-b)

-12

0

$ \begin{aligned}解：原式&=-xy(x²-6x+9) \\ &=-xy(x-3)² \\ \end{aligned}$

$ \begin{aligned}解：原式&=m³(a-2)-m(a-2) \\ &=m(a-2)(m+1)(m-1). \\ \end{aligned}$

$ \begin{aligned} 解：原式&=a[(x²+1)²-4x²] \\ &=a(x²+1+2x)(x²+1-2x) \\ &=a(x+ 1)²·(x-1)² \\ \end{aligned}$

$ \begin{aligned}解：原式&=(x²-4x+4)² \\ &=(x-2)⁴. \\ \end{aligned}$

$ \begin{aligned}解：原式&=a²(a-b)-2ab(a-b)+b²(a-b) \\ &=(a-b)(a²-2ab+b²) \\ &=(a-b)(a-b)² \\ &=(a-b)³ \\ \end{aligned}$

A

2024

3

2

$ \begin{aligned}解：原式&=(p-q)^{2m-1}[(p-q)^2-1] \\ &=(p-q)^{2m-1}(p-q+1)(p-q-1) \\ \end{aligned}$

$ \begin{aligned}解：原式&=(9x²-y²)² \\ &=(3x+y)²(3x-y)² \\ \end{aligned}$