Question

x(x^2+2)+2x(1-1/2x^2)=4

 

Answer 1

\(x.\left(x^2+2\right)+2x.\left(1-\dfrac{1}{2}x^2\right)=4\)

\(x^3+2x+2x-x^3=4\)

\(4x=4\)

\(\Rightarrow x=1\)

Answer 2

\(x\left(x^2+2\right)+2x\left(1-\dfrac{1}{2}x^2\right)=4< =>x^3+2x+2x-x^3=4< =>\left(x^3-x^3\right)+\left(2x+2x\right)=4< =>4x=4< =>x=1\)

Answer 3

\(x\left(x^2+2\right)+2x\left(1-\dfrac{1}{2}x^2\right)=4\)
\(\Rightarrow x^3+2x+2x-x^3=4\)
\(\Rightarrow4x=0\)

 

Vậy \(x=1\)