计算:x^2-9/4-x^2*x^2+x-2/x^2-4x+3,
问题描述：
计算:x^2-9/4-x^2*x^2+x-2/x^2-4x+3,
答
(x^2-9)/(4-x^2) * (x^2+x-2)/(x^2-4x+3)
=(x-3)(x+3)/(2-x)(2+x) * (x+2)(x-1)/[(x-1)(x-3)]
=(x+3)/(2-x)