(a-b)/(2a+2b)·(a^2+b^2)/(a^2-b^2)
=(a-b)/2(a+b)×(a²+b²)/(a+b)(a-b)
=(a²+b²)/2(a+b)²;
[(x+1)^2(1-x)^2]/[(x^2-1)^2]÷[(x-1)^2]/x^2-1
=（x+1）²×(x+1)(x-1)/(x-1)²;
=(x+1)³/(x-1);
手機(jī)提問的朋友在客戶端右上角評價點(diǎn)【滿意】即可.第二題能詳細(xì)點(diǎn)嗎[(x+1)^2(1-x)^2]/[(x^2-1)^2]÷[(x-1)^2]/x^2-1
=（x²-1）²/(x²-1)²×(x²-1)/(x-1)²
=（x-1)(x+1)/(x-1)²;
=(x+1)/(x-1);

抱歉，上面剛寫錯了[(x+1)^2(1-x)^2為什么會變成（x²-1）²（x+1)^2(1-x)^2

=(x+1)²(x-1)²
=[(x+1)(x-1)]²
=(x²-1)²;