(a-b/ab)^2•(b-a/-a)^-3÷1/(a^2-b^2)
a(a-1)-(a×a-b)=-5,求(a×a+b×b)÷2-ab
(a+b/a-b)²×2a-2b/3a+3b÷ab/a²-b²
因式分解a^+b^+2a^b+2ab^+a^+b^+3ab+a+b
化简 (a²+b²/a²-b²-a-b/a+b)÷2ab/(a-b)(a+b)&
计算:a/b(a-b)-b/a(a-b);(1/a+1/b)÷a²+2ab+b²/a+b.
3ab+3b²/b(a²+2ab+b²) ×a²-b²/a-b ÷b/
a+b/2ab
2AB/A+B
[(2b/a^2-b^2)+(a/a^2+ab)]÷3/a-b
(a-b)(a^2+ab+b) 化简
计算ab/(a+b-1)(a+b)+ab/(a+b)(a+b+1)+ab/(a+b+1)(a+b+2)+.+ab/(a+
先化简,再求值:[a/(a+b)-b/(b-a)-2ab/(a^2-b^2)]/(1/a-1/b),其中a+b=3,ab