$\frac{28}{15}$×3×$\frac{1}{4}$×3+( $\frac{8}{15}$- $\frac{79}{60}$):$\frac{47}{24}$
=$\frac{28×3×1×3}{15×4}$+( $\frac{32}{60}$-$\frac{79}{60}$)×$\frac{24}{47}$ =$\frac{252}{60}$+( $\frac{-47}{60}$)× $\frac{24}{47}$ =$\frac{252}{60}$- $\frac{47}{60}$× $\frac{24}{47}$ =$\frac{21}{5}$- $\frac{2}{5}$
=$\frac{19}{5}$
Cho mk 5 sao và ctlhn nha