当x=根号3/3,求代数式(x^2-3x)/(x-2)-[x+3/(2-x)]的值
问题描述:
当x=根号3/3,求代数式(x^2-3x)/(x-2)-[x+3/(2-x)]的值
答
(x^2-3x)/(x-2)-[x+3/(2-x)]=(x^2-3x)/(x-2)+[-x+3/(x-2)]=(x^2-3x)/(x-2)+[(-x^2+2x+3)/(x-2)]=(x^2-3x-x^2+2x+3)/(x-2)=(-x+3)/(x-2)将x=√3/3代入原式=(-√3/3+3)/(√3/3-2)=-(17+√3)/11