\(\left(x+2\right)^2=49\)
\(\Rightarrow\left[\begin{array}{nghiempt}\left(x+2\right)^2=7^2\\\left(x+2\right)^2=\left(-7\right)^2\end{array}\right.\)
\(\Rightarrow\left[\begin{array}{nghiempt}x+2=7\\x+2=-7\end{array}\right.\)
\(\Rightarrow\left[\begin{array}{nghiempt}x=7-2\\x=-7-2\end{array}\right.\)
\(\Rightarrow\left[\begin{array}{nghiempt}x=5\\x=-9\end{array}\right.\)
Vậy: \(x\in\left\{5;-9\right\}\)
\(49=7^2\) bài nì dể ẹt à
2+x=7
x=5 like mk nha
\(\left(x+2\right)^2=49\)
=> \(\left[\begin{array}{nghiempt}x+2=7\\x+2=-7\end{array}\right.\)\(\Leftrightarrow\left[\begin{array}{nghiempt}x=5\\x=-9\end{array}\right.\)
(x + 2 )2 = 49
( x + 2 )2 = 72
x + 2 = 7
x = 7 - 2
x = 5
Vậy x = 5
(x+2)2 = 49
( x +2 )2 = 72
x+2=7
=) x = 5
