4x³-18x²+27＝0

题目

4x³-18x²+27＝0

答案

4x^3-6x^2-12x^2+18x-18x+27=0
2x^2(2x-3)-6x(2x-3)-9(2x-3)=0
(2x-3)(2x^2-6x-9)=0
2x-3=0,得x=3/2
2x^2-6x-9=0,得x=[3±3√3]/2