Question

初二数学下册分式运算题.1.s-2t/3s * 6s²/s+2t2.x-y/x+y ÷ （x-y）²

Answer 1

1、原式=（s-2t)2s/(s+2t)=(2s²-4st)/(s+2t)2、原式=（x-y)/(x+y)× 1/(x-y)²=1/(x²-y²)3、原式=(u-2u)/(u+2u) - 2/(u+2u)(u-2u)=(u-2u)²/(u+2u)(u-2u) - 2/(u+2u)(u-2u)=-(u²-2)/3u&...