Question

(-1+1/5) elevado a 2 ÷ (0,4-1/5) elevado a 2 - 0,7 × √36/49

Answer 1

$(-1+ \frac{1}{5} )^{2} / ((0,4- \frac{1}{5})^{2} -7 . \sqrt{ \frac{36}{49} })= ( \frac{-4}{5} )^{2} / ((0,2)^{2} -7 . { \frac{6}{7} })$
$\frac{16}{25} / (0,04 - 6) = \frac{16}{25} / 5,96 = \frac{16}{25} / \frac{596}{100} = \frac{16}{25} . \frac{100}{596} = \frac{4}{1} . \frac{4}{149} = \frac{16}{149}$