Question

1.$5frac{4}{5} +frac{1}{13}$
2.$1frac{2}{5} -frac{5}{6}$
3.2 × $frac{3}{15}$

Answer 1

$5 frac{4}{5} + frac{1}{13} = 5 + frac{4}{5} +frac{1}{13} = \ = 5 + frac{4 times 13 + 5}{5 times 13} = 5 + frac{52 + 5}{65} = \ = 5 frac{57}{65}$
57=3*19
65=5*13

поэтому дробь 57/65 несократима

$1 frac{2}{5} - frac{5}{6} = frac{7}{5} - frac{5}{6} = \ = frac{7 times 6 - 5 times 5}{5 times 6} = \ = frac{42 - 25}{30} = frac{17}{30}$

$2 times frac{3}{15} = 2 times frac{3}{3 times 5} = 2 times frac{1}{5} = frac{2}{5}$