Question

помагите 2 задания 579,580

Answer 1

N579
2) 2/9-21/80=7/120
N580
2)1/3+1/2=2/6+3/6=5/6

Answer 2

$\frac{4}{9} \times \frac{3}{4} + \frac{2}{3} = \frac{1}{3} + \frac{2}{3} = 1$
$2 \frac{3}{10} \times 2 \frac{1}{2} + \frac{1}{2} = \frac{3}{5} + \frac{1}{2} = \frac{11}{10} = 1 \frac{1}{10}$