Question

21/20 - 3/8 - 1/5 = ?

7,8 - ( 1/4 + 1/6 ) = ?

Answer 1

1)0.475

2)0.45833333333 округлим 0.459

Answer 2

$\frac{21}{20} - \frac{3}{8} - \frac{1}{5} = \frac{42 - 15 - 8}{40} = \frac{19}{40} \\ \\ 7.8 - ( \frac{1}{4} + \frac{1}{6} ) = \frac{39}{5 - \frac{5}{12} } = \frac{443}{60}$