Question

1).(3x+2)²=11

2).(7x-1)²=(2-x)²

^{giúp mk vs ạ} 

Answer 1

1: \(\left(3x+2\right)^2=11\)

=>\(\left[{}\begin{matrix}3x+2=\sqrt{11}\\3x+2=-\sqrt{11}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}3x=\sqrt{11}-2\\3x=-\sqrt{11}-2\end{matrix}\right.\)

=>\(\left[{}\begin{matrix}x=\dfrac{\sqrt{11}-2}{3}\\x=\dfrac{-\sqrt{11}-2}{3}\end{matrix}\right.\)

2: \(\left(7x-1\right)^2=\left(2-x\right)^2\)

=>\(\left(7x-1\right)^2-\left(x-2\right)^2=0\)

=>\(\left(7x-1-x+2\right)\left(7x-1+x-2\right)=0\)

=>(6x+1)(8x-3)=0

=>\(\left[{}\begin{matrix}6x+1=0\\8x-3=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{1}{6}\\x=\dfrac{3}{8}\end{matrix}\right.\)