Toán Lớp 5: 1/3 + 2/5 – 7/15. 3/4: 7/8 nhân 14/15

$\frac{1}{3}$ $+$ $\frac{2}{5}$ $-$ $\frac{7}{15}$

$=$ $\frac{5}{15}$ $+$ $\frac{6}{15}$ $-$ $\frac{7}{15}$

$=$ $\frac{5+6-7}{15}$

$=$ $\frac{4}{15}$

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$\frac{3}{4}$ $÷$ $\frac{7}{8}$ $×$  $\frac{14}{15}$ 

$=$ $\frac{3}{4}$ $×$ $\frac{8}{7}$ $×$  $\frac{14}{15}$ 

$=$ $\frac{3×8×14}{4×7×15}$

$=$ $\frac{336}{420}$

$=$ $\frac{4}{5}$ 

$Chúc$ $bạn$ $học$ $tốt!$