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

TRẢ LỜI

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

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

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

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

   ————————————————————————————————————–

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

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

   $=$ $\frac{3×8×14}{4×7×15}$

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

   $=$ $\frac{4}{5}$ 

   $Chúc$ $bạn$ $học$ $tốt!$

   Trả lời
2. 1/3 + 2/5 – 7/(15).

   = (1 xx 5)/(3 xx 5) + (2 xx 3)/(5 xx 3) – 7/(15)

   = 5/(15) + 6/(15) – 7/(15)

   = 4/(15)

   3/4 : 7/8 xx (14)/(15)

   = 3/4 xx 8/7 xx (14)/(15)

   = 6/7 xx (14)/(25)

   = 4/5

   Trả lời