a)
\(\left(2x-3\right)^2=36\)
\(\Rightarrow\left[\begin{array}{nghiempt}\left(2x-3\right)^2=6^2\\\left(2x-3\right)^2=\left(-6\right)^2\end{array}\right.\)
\(\Rightarrow\left[\begin{array}{nghiempt}2x-3=6\\2x-3=-6\end{array}\right.\)
\(\Rightarrow\left[\begin{array}{nghiempt}x=\frac{9}{2}\\x=-\frac{3}{2}\end{array}\right.\)
b)
\(\left(x+2\right)^4=16\)
\(\Rightarrow\left[\begin{array}{nghiempt}\left(x+2\right)^4=2^4\\\left(x+2\right)^4=\left(-2\right)^4\end{array}\right.\)
\(\Rightarrow\left[\begin{array}{nghiempt}x+2=2\\x+2=-2\end{array}\right.\)
\(\Rightarrow\left[\begin{array}{nghiempt}x=0\\x=-2\end{array}\right.\)
c)
\(\left(3x+2\right)^3=81\)
\(\Rightarrow\left(3x+2\right)^3=3^3\)
\(\Rightarrow3x+2=3\)
\(\Rightarrow x=\frac{1}{3}\)
a) \(\left(2x-3\right)^2=36\)
\(\Leftrightarrow\left(2x-3\right)^2=6^2=\left(-6\right)^2\)
\(\Leftrightarrow\begin{cases}2x-3=6\\2x-3=-6\end{cases}\)\(\Leftrightarrow\begin{cases}2x=9\\2x=-3\end{cases}\)\(\Leftrightarrow\begin{cases}x=4.5\\x=-1.5\end{cases}\)
Vậy.....
b) \(\left(x+2\right)^4=16\)
\(\Leftrightarrow\left(x+2\right)^4=2^4=\left(-2\right)^4\)
\(\Leftrightarrow\begin{cases}x+2=2\\x+2=-2\end{cases}\)\(\Leftrightarrow\begin{cases}x=0\\x=-4\end{cases}\)
Vậy........