(2a+b)(2a-b)+a(2a+b) =(2a+b)(2a-b+a) =(2a+b)(3a-b)能说明理由吗?

-2a(a+b)+b(a+b) (a+2b)(a-2b)+(a-b)(a+b)-2(a-3b)(a-b) 5(a*a*b-3*a*a*b)-2*(a*a*b-7*a*b*b) 化简：a-[b-2a-(a-b)] -a-b+2b^2/a+b 化简：|a+b|+|b-a|+|2b| |a+b|-|b-a|+|2b|化简哦! a-b+2b²/a+b 通分a-b,2b^/a+b 化简（2a-b/a+b-b/a-b）÷a-2a/a-b (2/3a)-[2/(a+b)]{[(a+b)/3a]-a-b}÷[(a-b)/b] (a/a-b-a/a+b)(a+b)(a-b)/2b 化简(2a-b/a+b-b/a-b)除以a-2b/a+b 计算：((a+b)(a-b)-(a-b)^2+2b(a-b))/4(a-b) 化简(2a-b/a+b-b/a-b)除以a-2b/a +b 化简：{[(2a-b)/(a+b)]-[b/(a-b)]}÷[(a-2b)/(a+b)] 计算·[(2a+-b)/(a+b)-b/(a+b)]/(a-2b)/(a+b) (a-b)(a+b)²-(a+b)(a-b)²+2b(a²+b²)