化简求值 (3/x-1 -x-1)÷ x-2/x^2-2x+1,其中x=-√2
问题描述:
化简求值 (3/x-1 -x-1)÷ x-2/x^2-2x+1,其中x=-√2
答
[3/(x-1) -x-1]÷ (x-2)/(x^2-2x+1)
=[(3-x^2+1)/(x-1)]*(x-1)^2/(x-2)
=-(x+2)(x-1)
=-(x^2+x-2),
当x=-√2 时原式=√2.