Đáp án + Giải thích các bước giải:
a)
Cách 1:
$\bigg(\dfrac{11}{15} - \dfrac{7}{15}\bigg) \times \dfrac{2}{7}\\$
$=\dfrac{4}{15} \times \dfrac{2}{7}\\$
$=\dfrac{8}{105}\\$
Cách 2:
$\bigg(\dfrac{11}{15} - \dfrac{7}{15}\bigg) \times \dfrac{2}{7}\\$
$=\dfrac{11}{15} \times \dfrac{2}{7} - \dfrac{7}{15} \times \dfrac{2}{7}\\$
$=\dfrac{22}{105} - \dfrac{14}{105}\\$
$=\dfrac{8}{105}\\$
b)
Cách 1:
$\bigg(\dfrac{5}{11} + \dfrac{3}{11}\bigg) : \dfrac{3}{4}\\$
$=\dfrac{8}{11} : \dfrac{3}{4}\\$
$=\dfrac{8}{11} \times \dfrac{4}{3}\\$
$=\dfrac{32}{33}\\$
Cách 2:
$\bigg(\dfrac{5}{11} + \dfrac{3}{11}\bigg) : \dfrac{3}{4}\\$
$=\dfrac{5}{11} \times \dfrac{4}{3} + \dfrac{3}{11} \times \dfrac{4}{3}\\$
$=\dfrac{20}{33} + \dfrac{12}{33}\\$
$=\dfrac{32}{33}\\$
Mong hay nhất😄😄😄
