(a+b)²-(a-b)²=(a+b+a-b)(a+b-a+b)=2a*2b=4ab望采纳
解法一:(a+b)²-(a-b)²=(a+b+a-b)(a+b-a+b)=2a*2b=4ab解法二:(a+b)^2-(a-b)^2=a^2+2ab+b^2-a^2+2ab-b^2=4ab
(a+b)^2-(a-b)^2=a^2+2ab+b^2-a^2+2ab-b^2=4ab
(a+b)^2-(a-b)^2=4ab
(a+b)的平方-(a-b)的平方=4ab
4ab