Question

TÌM x

1, 720 : [ 41 - ( 2 . x -5 ) ] = 2.2.2 .5

2, ( 2 . x + 1 ) ² = 625

Giup mình nha

Answer 1

a, \(720:\left[41-\left(2x-5\right)\right]=2.2.2.5\)

\(720:\left[41-\left(2x-5\right)\right]=40\)

\(41-\left(2x-5\right)=18\)

\(\Leftrightarrow2x-5=23\)

\(\Leftrightarrow2x=28\)

\(\Leftrightarrow x=14\)

Vậy ....

b, \(\left(2x+1\right)^2=625\)

\(\Leftrightarrow\left[{}\begin{matrix}\left(2x+1\right)^2=25^2\\\left(2x+1\right)^2=\left(-25\right)^2\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}2x+1=25\\2x+1=-25\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=12\\x=-13\end{matrix}\right.\)

Vậy ...