初一计算与因式分解：①(3a-b)(a+b)(a-b)² ②2(x+2)(x-2)-(x+1)² ③x²(x-y)+(y-x)

题目

初一计算与因式分解：①(3a-b)(a+b)(a-b)² ②2(x+2)(x-2)-(x+1)² ③x²(x-y)+(y-x)
④x²-y²-x+y ⑤3a³-6a²+3a,快,

答案

①(3a-b)(a+b)(a-b)² =(3a²+3ab-ab-b²)(a²-2ab+b²)3 4 =(3a²+2ab-b²)(a²-2ab+b²) =3a4-6a3b+3a²b...