因式分解(1)(2a+3b)²-(a-2b)²(2)3a的3n次方-12a的2n次方b+12a的n次方b²
问题描述:
因式分解(1)(2a+3b)²-(a-2b)²(2)3a的3n次方-12a的2n次方b+12a的n次方b²
答
(1)(2a+3b)²-(a-2b)²
=(2a+3b+a-2b)(2a+3b-a+2b)
=(3a+b)(a+5b)
(2)3a的3n次方-12a的2n次方b+12a的n次方b²
=3a^3n-12a^2n*b+12a^n*b2
=3a^n(a^2n-4a^n*b+4b²)
=3a^n(a^n-2b)²