Question

解下列方程：y/y+2-y-1/y-2=0;x+3/x-7+x+7/x-3=2.

Answer 1

y/y+2-y-1/y-2=0

y(y-2)-(y-1)(y+2)=0

y²-2y-y²-y+2=0

-3y+2=0

y=2/3

x+3/x-7+x+7/x-3=2.

(x+3)(x-3)+(x+7)(x-7)=2(x-3)(x-7)

x²-9+x²-49=2x²-20x+42

20x=100

∴x=5

经检验,以上都是方程的根.