分解因式1、0.81a²-16b²2、4/9m²-0.01²

Question

分解因式 1、 0.81a²-16b² 2、4/9m²-0.01²

Answer 1

0.81a²-16b² =（0.9a+4b）(0.9a-4b)
4/9m²-0.01² =(2/3m+0.1)(2/3m-0.1)