Question

1、解分式方程：X减2分之X 减1等于4减X²分之2

2、化简求值。X²减1分之X²减2X÷（X减1减X加1分之2X减1）其中X等于2

Answer 1

1、解分式方程：X减2分之X 减1等于4减X²分之2
x/(x-2) -1=2/(4-x²)
x/(x-2) -1=-2/(x²-4)
x(x+2) -(x²-4)=-2
x²+2x -x²+4=-2
2x=-6
x=-3
经检验x=-3是方程的解
2
X²减1分之X²减2X÷（X减1减X加1分之2X减1）其中X等于2
=(x²-2x)/(x²-1) ÷（x-1 - (2x-1)/(x+1)）
=x(x-2)/(x²-1) ÷ ((x-1)(x+1)-(2x-1))/(x+1)
=x(x-2)/(x²-1) ÷ (x^2-1-2x+1)/(x+1)
=x(x-2)/(x²-1) *(x+1)/ x(x-2)
=1/(x-1)
=1/(2-1)
=1