$\text{Bài 1:}$
$\text{5 . ( x - 3 ) = 125}$
$\text{( x - 3 ) = 125 : 5}$
$\text{x - 3 = 25}$
$\text{x = 25 + 3}$
$\text{x = 28}$
$\text{Vậy x = 28}$
$\text{Bài 2:}$
$\text{205 - 7 . ( x + 5 ) = 100}$
$\text{7 . ( x + 5 ) = 205 - 100}$
$\text{7 . ( x +5 ) = 105}$
$\text{x + 5 = 105 : 7}$
$\text{x + 5 = 15}$
$\text{x = 15 - 5}$
$\text{x = 10}$
$\text{Vậy x = 10}$
$\text{Bài 3:}$
$\text{14 - x - 4 = $4^{2}$ . 4}$
$\text{14 - x - 4 = 16 . 4}$
$\text{14 - x - 4 = 64}$
$\text{14 - x = 64 + 4}$
$\text{14 - x = 68}$
$\text{x = 14 - 68}$
$\text{x = -54}$
$\text{Vậy x = -54}$
$\text{Bài 4:}$
$\text{70 - 5 . ( x - 3 ) = 4}$
$\text{5 . ( x - 3 ) = 70 - 4}$
$\text{5 . ( x - 3 ) = 66}$
$\text{x - 3 = 66 : 5}$
$\text{x - 3 = $\frac{66}{5}$}$
$\text{x = $\frac{66}{5}$ + 3}$
$\text{x = $\frac{81}{5}$}$
$\text{Vậy x = $\frac{81}{5}$}$
$\text{Bài 5:}$
$\text{2 . x - 20 = 43 : 43}$
$\text{2 . x - 20 = 1}$
$\text{2 . x = 1 + 20}$
$\text{2 . x = 21}$
$\text{x = 21 : 2}$
$\text{x = $\frac{21}{2}$}$
$\text{Vậy x = $\frac{21}{2}$}$
$#Bin$
