Question

x为何值时,下列公式的值为0; (1)x^2-3x+2分之x (2)x^2-x-2分之x-2 (3)x^2-3x-4分之

Answer 1

(1)x/(x^2-3x+2)=x/(x-1)(x-2)=0,x=0

(2)(x-2)/(x^2-x-2)=(x-2)/(x-2)(x+1)=0,无解

(3)(x^2-16)/(x^2-3x-4)=(x+4)(x-4)/(x-4)(x+1)=0,x=-4