Đáp án:
Giải thích các bước giải:
a. $\frac{x}{5}$ = $\frac{2}{3}$
⇒ 3x = 5.2
3x = 10
x = 10 : 3
x = $\frac{10}{3}$
b. $\frac{x}{3}$ - $\frac{1}{2}$ = $\frac{1}{5}$
$\frac{x}{3}$ = $\frac{1}{5}$ + $\frac{1}{2}$
$\frac{x}{3}$ = $\frac{2}{10}$ + $\frac{5}{10}$
$\frac{x}{3}$ = $\frac{7}{10}$
⇒ 10x = 3.7
10x = 21
x = 21 : 10
x = $\frac{21}{10}$
c. $\frac{x}{5}$ + $\frac{1}{2}$ = $\frac{6}{10}$
$\frac{x}{5}$ = $\frac{6}{10}$ - $\frac{1}{2}$
$\frac{x}{5}$ = $\frac{6}{10}$ - $\frac{5}{10}$
$\frac{x}{5}$ = $\frac{1}{10}$
⇒ 10x = 5.1
10x = 5
x = 5 : 10
x = $\frac{1}{2}$
d. x + $\frac{3}{15}$ = $\frac{1}{3}$
x = $\frac{1}{3}$ - $\frac{3}{15}$
x = $\frac{5}{15}$ - $\frac{3}{15}$
x = $\frac{8}{15}$