a
($\frac{1}{3}$) ²×3-$\frac{2}{3}$
=$\frac{1}{9}$ ×3-$\frac{2}{3}$
=$\frac{1}{3}$-$\frac{2}{3}$
=$\frac{-1}{3}$
b
-2$\frac{1}{5}$ $\frac{7}{9}$ +$\frac{4}{5}$ $\frac{7}{9}$
=$\frac{7}{9}$($\frac{-2}{5}$+$\frac{4}{5}$)
=$\frac{7}{9}$ $\frac{2}{5}$
=$\frac{14}{ 45}$
c
$\sqrt[]{64}$ :$\frac{16}{5}$ -$\sqrt[]{\frac{25}{9}}$ \\ =$\frac{8*5}{16}$ -$\frac{5}{3}$ \\ =$\frac{5}{2}$ -$\frac{5}{3}$\\ =$\frac{5}{6}$
Có gì cho mk xin ctlhn nha
