Question

Tìm x 

Answer 1

c) \(\left(3x-9\right)^2=0\)

\(\Leftrightarrow3x-9=0\Leftrightarrow3x=9\Leftrightarrow x=3\)

d) \(36-12x+x^2=0\)

 \(\Leftrightarrow\left(x-6\right)^2=0\)

\(\Leftrightarrow x-6=0\Leftrightarrow x=6\)

e) \(4x^2+12x+9=0\)

\(\Leftrightarrow\left(2x+3\right)^2=0\)

\(\Leftrightarrow2x+3=0\Leftrightarrow x=-\dfrac{3}{2}\)

f) \(x^2-16=0\)

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

\(\Leftrightarrow\left[{}\begin{matrix}x=4\\x=-4\end{matrix}\right.\)