已知(x^2+4x+3)/(x+1)=0,先化简后求x^2/(x-3)+9/(3-x)

问题描述:

已知(x^2+4x+3)/(x+1)=0,先化简后求x^2/(x-3)+9/(3-x)
已知(x^2+4x+3)/(x+1)=0,先化简后求
x^2/(x-3)+9/(3-x)

(x^2+4x+3)/(x+1)=0
(x+1)*(x+3)/(x+1)=0
x+3=0
x=-3
x^2/(x-3)+9/(3-x)=(x^2-9)/(x-3)=(x+3)*(x-3)/(x-3)=x+3=0