Question

(2x-1)²=25

Answer 1

\(\left(2x-1\right)^2=25\)

\(\Leftrightarrow\left[{}\begin{matrix}\left(2x-1\right)^2=5^2\\\left(2x-1\right)^2=\left(-5\right)^2\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}2x-1=5\\2x-1=-5\end{matrix}\right.\)

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

Vậy ..

Answer 2

\(\left(2x-1\right)^2=25\\ \Leftrightarrow\left(2x-1\right)^2=\left(\pm5\right)^2\\ \Rightarrow\left\{{}\begin{matrix}2x-1=5\\2x-1=-5\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}2x=6\\2x=-4\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=3\\x=-2\end{matrix}\right.\)

Answer 3

(2x-1)² = 25

\(\Rightarrow\) 2x-1=25 hoặc 2x-1=-25

th1

2x-1=25

2x = 26

x = \(\dfrac{26}{2}\)

x = 13

th2

2x-1=-25

2x=-24

x= \(\dfrac{-24}{2}\)

x = -12

vậy x = 13 ; x=-12