Tính: d) ( 1/25 − 0 , 4 )^2 : 9/125 − [ ( 1(1/3) − 2/5 ) . 3/7 ]

d) ${(\frac{1}{25}-0,4)}^2:\frac{9}{125}-[(1\frac{1}{3}-\frac{2}{5}).\frac{3}{7}]$

$={(\frac{1}{25}-\frac{2}{5})}^2.\frac{125}{9}-[(\frac{4}{3}-\frac{2}{5}).\frac{3}{7}]$

$={\left(\frac{-9}{25}\right)}^2.\frac{125}{9}-[\frac{14}{15}.\frac{3}{7}]$

$=\frac{9^2}{{25}^2}.\frac{125}{9}-\frac{2}{5}=\frac{{\left(3^2\right)}^2}{{\left(5^2\right)}^2}.\frac{5^3}{3^2}-\frac{2}{5}$

$=\frac{3^4}{5^4}.\frac{5^3}{3^2}-\frac{2}{5}=\frac{3^2}{5}-\frac{2}{5}$

$=\frac{9}{5}-\frac{2}{5}=\frac{7}{5}$