计算:-4/(x^2-4)-1/(2-x) x-7/(x-3)+1/3-x
问题描述:
计算:-4/(x^2-4)-1/(2-x) x-7/(x-3)+1/3-x
答
-4/(x^2-4)-1/(2-x)
=-4/(x+2)(x-2) + 1/(x-2)
=(-4+x+2)/(x+2)(x-2)
=(x-2)/(x+2)(x-2)
=1/(x+2)
x-7/(x-3)+1/(3-x)
=x - 7/(x-3) - 1/(x-3)
=(x^2-3x-7-1)/(x-3)
=(x^2-3x-8)/(x-3)第二题貌似错了(x-7)/(x-3)+1/(3-x)x-7 是分子吗?=(x -7)/(x-3) - 1/(x-3)=(x-7-1)/(x-3)=(x-8)/(x-3)