Question

4(a+2b)的完全平方减25(a-b)的完全平方 (因式分解)

Answer 1

4(a+2b)²-25(a-b)²
=[2(a+2b)+5(a-b)][2(a+2b)-5(a-b)]
=(7a-b)(-3a+9b)
=3(7a-b)(3b-a)

Answer 2

[2（a+2b）+5(a-b)]*[2（a+2b）-5(a-b)]
=3(3b-a) *(7a-b)

因式分解a^2-b^2=(a+b)*(a-b)