a) \(x^2+x=6\)
\(\Rightarrow x^2+x-6=0\)
\(\Rightarrow x^2-2x+3x-6=0\)
\(\Rightarrow\left(x^2-2x\right)+\left(3x-6\right)=0\)
\(\Rightarrow x\left(x-2\right)+3\left(x-2\right)=0\)
\(\Rightarrow\left(x-2\right)\left(x+3\right)=0\)
\(\Rightarrow x-2=0\) hoặc \(x+3=0\)
1) x-2 =0 => x=2
2) x+3=0 => x=-3
vậy x=2 ; x=-3
b)
\(6x^3+x^2=2x\)
\(\Rightarrow6x^3+x^2-2x=0\)
\(\Rightarrow6x^3-3x^2+4x^2-2x=0\)
\(\Rightarrow\left(6x^3-3x^2\right)+\left(4x^2-2x\right)=0\)
\(\Rightarrow3x^2\left(2x-1\right)+2x\left(2x-1\right)=0\)
\(\Rightarrow x\left(2x-1\right)\left(3x+2\right)=0\)
\(\Rightarrow x=0\) hoặc \(2x-1=0\) hoặc \(3x+2=0\)
1) x=0
2) 2x-1=0 => 2x=1=> x=\(\dfrac{1}{2}\)
3) 3x+2=0 => 3x=-2 => x= \(-\dfrac{2}{3}\)
Vậy \(x=0\); \(x=\dfrac{1}{2}\);\(x=-\dfrac{2}{3}\)