Question

Bài 5:Tìm x, biết :

a) (x+2)(x^2-2x+4)-x(x-1)(x+1)+3x=2 

b)8/9x(2x^2-3)=0

 

Answer 1

a: \(\Leftrightarrow x^3+8-x^3+x+3x=2\)

\(\Leftrightarrow4x=-6\)

hay \(x=-\dfrac{3}{2}\)

Answer 2

a) \(\Rightarrow x^2+8-x^3+x+3x=2\)

\(\Rightarrow4x=-6\Rightarrow x=-\dfrac{3}{2}\)

b) \(\Rightarrow\left[{}\begin{matrix}x=0\\2x^2=3\end{matrix}\right.\)\(\Rightarrow\left[{}\begin{matrix}x=0\\x^2=\dfrac{3}{2}\end{matrix}\right.\)\(\Rightarrow\left[{}\begin{matrix}x=0\\x=\pm\sqrt{\dfrac{3}{2}}\end{matrix}\right.\)