Question

Tìm x

\(\left(2x-3\right)^2-49=0\)

Answer 1

`(2x-3)^2 -49=0`

`<=>(2x-3)^2=0+49`

`<=>(2x-3)^2=49`

`<=>(2x-3)^2=+-7^2`

\(\Leftrightarrow\left[{}\begin{matrix}2x-3=7\\2x-3=-7\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}2x=10\\2x=-4\end{matrix}\right.\)

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

Answer 2

\(\left(2x-3\right)^2-49=0\)

\(\left(2x-3\right)^2-7^2=7\)

\(\left(2x-3-7\right).\left(2x-3+7\right)=0\)

\(\left(2x-10\right).\left(2x+4\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}2x=10\\2x=-4\end{matrix}\right.\)

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

vậy x = 5 hoặc x = -2

 

Answer 3

⇒(2x-3)²=49

⇒(2x-3)²=7²

⇒2x-3=7

⇒2x=10

⇒x=5

Vậy x=5

#hoc24

Answer 4

\(\Leftrightarrow\left(2x-3\right)^2=49\)

\(\Leftrightarrow\left(2x-3\right)^2=7^2\)

\(\Rightarrow2x-3=7\)

\(\Leftrightarrow2x=10\)

\(\Leftrightarrow x=5\)