(x的2次方-3x+2)分之(x-1)-(x的2次方+3x+2)分之(x+1)-(x的2次方-4)分之x的2次方
问题描述:
(x的2次方-3x+2)分之(x-1)-(x的2次方+3x+2)分之(x+1)-(x的2次方-4)分之x的2次方
答
=(x-1)/(x-2)(x-1)-(x+1)/(x+2)(x+1)-x²/(x+2)(x-2)
=1/(x-2)-1/(x+2)-x²/(x+2)(x-2)
=[(x+2)-(x-2)-x²]/(x+2)(x-2)
=(4-x²)/(x²-4)
=-1