48+13(a-b)-(a-b)^2
48+13(a-b)-(a-b)^2
a-b+2b²/a+b
化简:{[(2a-b)/(a+b)]-[b/(a-b)]}÷[(a-2b)/(a+b)]
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)
计算·[(2a+-b)/(a+b)-b/(a+b)]/(a-2b)/(a+b)
化简(2a-b/a+b-b/a-b)除以a-2b/a+b
(a-b)(a+b)²-(a+b)(a-b)²+2b(a²+b²)
(a/a-b-a/a+b)(a+b)(a-b)/2b
(b-a)*(b-a)+(b-a)*2*a等于多少?
a+b>a-b,
(a-b)(a b)