已知x=1.5 先分解因式再求值 8x^3(x-3)+12x^2(3-x)
问题描述：
已知x=1.5 先分解因式再求值 8x^3(x-3)+12x^2(3-x)
答
f(x)=8x^3(x-3)+12x^2(3-x)
= 4x^2(x-3)(2x-3)
x= 1.5
f(1.5) = 4(1.5)^4(1.5-3)(2(1.5)-3) =0