Question

9(a+b)^2-30(a-b)(a+b)+25(a-b）^2因式分解

Answer 1

原式=[3(a+b)]²-2[3(a+b)][5(a-b)]+[5(a-b)]²

=[3(a+b)-5(a-b)]²

=(3a+3b-5a+5b)²

=(-2a+8b)²

=(-2)²(a-4b)²

=4(a-4b)²