Question

[Plinh]

Tìm x biết: 4x².(x-2)-x+2=0 x³+27+(x+3).(x-9)

Answer 1

[Plinh]

x³+27+(x+3).(x-9)=0 nha mk ghi nhầm 

Answer 2

[Lấp La Lấp Lánh]

\(x^3+27+\left(x+3\right)\left(x-9\right)=0\)

\(\Leftrightarrow\left(x+3\right)\left(x^2-3x+9\right)+\left(x+3\right)\left(x-9\right)=0\)

\(\Leftrightarrow\left(x+3\right)\left(x^2-2x\right)=0\)

\(\Leftrightarrow x\left(x+3\right)\left(x-2\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=2\\x=-3\end{matrix}\right.\)