Вычислите: №833 а) 1/10 + 7/100 б) 21/100 + 1/10 в) 3/5 + 9/10 г) 2/3 + 5/6 №835 а) 1/6 +...

883.
а)
$\frac{1}{10} + \frac{7}{100} = \frac{1}{10} \times \frac{10}{10} + \frac{7}{100} = \frac{1 \times 10}{100} + \frac{7}{100} = \frac{10 + 7}{100} = \frac{17}{100} = 0.17$
б)
$\frac{21}{100} + \frac{1}{10} = \frac{21}{100 } + \frac{1}{10} \times \frac{1}{10} = \frac{21}{100} + \frac{1 \times 10}{100} = \frac{21 + 10}{100} = \frac{31}{100} = 0.31$
в)
$\frac{3}{5} + \frac{9}{10} = \frac{3}{5} \times \frac{2}{2} + \frac{9}{10} = \frac{3 \times 2}{10} + \frac{9}{10} = \frac{3 \times 2 + 9}{10} = \frac{15}{10} = \frac{3}{2} = 1.5$
г)
$\frac{2}{3 } + \frac{5}{6} = \frac{2}{3} \times \frac{2}{2} + \frac{5}{6} = \frac{2 \times 2}{6} + \frac{5}{6} = \frac{2 \times 2 + 5}{6} = \frac{9}{6} = \frac{3}{2} = 1.5$