Question

当m为何值时,关于X的方程m/(x^2-x-2)=x/(x+1)-(x-1)/(x-2)的解是负数

Answer 1

m/(x^2-x-2)=x/(x+1)-(x-1)/(x-2)

m/(x-2)(x+1)=[x(x-2)-(x-1)(x+1)]/(x-2)(x+1)

m=x(x-2)-(x-1)(x+1)=x^2-2x-x^2+1=1-2x

x=(1-m)/2

解是负数

x0

1-m1

分母不等于0

x-2不等于0,x+1不等于0

x不等于-1

若x=-1

(1-m)/2=-1

1-m=-2

m=3

所以m>1且m不等于3