Question

 

Tìm x biếta) |x+1l+2x=-2b)x^2-6x+9=1

Answer 1

a) \(\left|x+1\right|+2x=-2\)

\(\Leftrightarrow\left|x+1\right|+2\left(x+1\right)=0\)

\(\Leftrightarrow x+1=0\Leftrightarrow x=-1\)

b) \(x^2-6x+9=1\)

\(\Leftrightarrow x^2-6x+8=0\)

\(\Leftrightarrow x^2-2x-4x+8=0\)

\(\Leftrightarrow x\left(x-2\right)-4\left(x-2\right)=0\)

\(\Leftrightarrow\left(x-2\right)\left(x-4\right)=0\)

\(\Leftrightarrow\left[\begin{array}{nghiempt}x-2=0\\x-4=0\end{array}\right.\)\(\Leftrightarrow\left[\begin{array}{nghiempt}x=2\\x=4\end{array}\right.\)