đk : x>= -1/3
\(x^2+x-4\sqrt{3x+1}+8-2=0\)
\(\Leftrightarrow-4\left(\sqrt{3x+1}-2\right)+\left(x-1\right)\left(x+2\right)=0\)
\(\Leftrightarrow-4\left(\dfrac{3x+1-4}{\sqrt{3x+1}+2}\right)+\left(x-1\right)\left(x+2\right)=0\)
\(\Leftrightarrow-4\left(\dfrac{3x-3}{\sqrt{3x+1}+2}\right)+\left(x-1\right)\left(x+2\right)=0\)
\(\Leftrightarrow\dfrac{-12\left(x-1\right)}{\sqrt{3x+1}+2}+\left(x-1\right)\left(x+2\right)=0\)
\(\Leftrightarrow\left(x-1\right)\left(-\dfrac{12}{\sqrt{3x+1}+2}+x+2\ne0\right)=0\Leftrightarrow x=1\left(tm\right)\)
Đúng 2
Bình luận (0)
