$\text{a) 2x + $\dfrac{2}{4}$=$\dfrac{5}{2}$}$
$\text{⇒ 2x = $\dfrac{5}{2}$ - $\dfrac{2}{4}$}$
$\text{⇒ 2x = $\dfrac{10}{4}$ - $\dfrac{2}{4}$}$
$\text{⇒ 2x = $\dfrac{8}{4}$}$
$\text{⇒ 2x = 2}$
$\text{⇒ x = 1}$
$\text{Vậy x = 1.}$
$\text{b) 35 ÷ x + 1 = 8}$
$\text{⇒ 35 ÷ x = 8 - 1}$
$\text{⇒ 35 ÷ x = 7}$
$\text{⇒ x = 35 ÷ 7}$
$\text{⇒ x = 5}$
$\text{Vậy x = 5.}$
$\text{c) 20x + 4 ÷ 2 - 5 = 17}$
$\text{⇒ 20x + 2 - 5 = 17}$
$\text{⇒ 20x - 3 = 17}$
$\text{⇒ 20x = 17 + 3}$
$\text{⇒ 20x = 20}$
$\text{⇒ x = 1}$
$\text{Vậy x = 1.}$
$\text{d) 15 ÷ 5.2 + 4 = 10}$
$\text{⇒ 3.2 + 4 = 10}$
$\text{⇒ 6 + 4 = 10}$
$\text{e) 2x + 4 ÷ 2 - 5 = 1}$
$\text{⇒ 2x + 2 - 5 = 1}$
$\text{⇒ 2x - 3 = 1}$
$\text{⇒ 2x = 1 + 3}$
$\text{⇒ 2x = 4}$
$\text{⇒ x = 4 ÷ 2}$
$\text{⇒ x = 2}$
$\text{Vậy x = 2.}$
