a) `x` + $\dfrac{3}{8}$ = $\dfrac{4}{3}$
⇒ `x` = $\dfrac{4}{3}$ - $\dfrac{3}{8}$
⇒ `x` = $\dfrac{32}{24}$ - $\dfrac{9}{24}$
⇒ `x` = $\dfrac{23}{24}$
Vậy `x` = $\dfrac{23}{24}$
b) `x` - $\dfrac{4}{5}$ = $\dfrac{7}{6}$
⇒ `x` = $\dfrac{7}{6}$ + $\dfrac{4}{5}$
⇒ `x` = $\dfrac{35}{30}$ + $\dfrac{24}{30}$
⇒ `x` = $\dfrac{59}{30}$
Vậy `x` = $\dfrac{59}{30}$
c) `x` x $\dfrac{1}{9}$ = $\dfrac{21}{8}$
⇒ `x` = $\dfrac{21}{8}$ : $\dfrac{1}{9}$
⇒ `x` = $\dfrac{21}{8}$ x 9
⇒ `x` = $\dfrac{189}{8}$
Vậy `x` = $\dfrac{189}{8}$
d) `x` : $\dfrac{8}{3}$ `= 5`
⇒ `x` `= 5` x $\dfrac{8}{3}$
⇒ `x` = $\dfrac{40}{3}$
Vậy `x` = $\dfrac{40}{3}$