:(a+2b)²-a²-2ab

问题描述:

:(a+2b)²-a²-2ab

2b(a+2b)

(a+2b)2-a2-2ab=a2+4b2+4ab-a2-2ab=4b2+2ab

(a+2b)²-a²-2ab
=a²+4ab+4b²-a²-2ab
=4b²+2ab
=2b(2b+a)

2b(2b+2)

(a+2b)²-a²-2ab
=a²+4ab+4b²-a²-2ab
=2ab+4b²
=2b(a+2b)