-x³+7x-6
问题描述:
-x³+7x-6
答
-x^3-7x-60
x^3-x-6x+6>0
x(x^2-1)-6(x-1)>0
x(x+1)(x-1)-6(x-1)>0
(x-1)(x(x+1)-6)>0
(x-1)(x^2+x-6)>0
(x-1)(x-2)(x+3)>0
解得x∈(-3,1)∪(2,正无穷)