Question

1) 15 42 56 -+ 20 30 40
10 и 11 номер
пожалуйста ​

Answer 1

Пошаговое объяснение:

Nr. 10

1)

$\frac{15}{20} + \frac{42}{30} + \frac{56}{40} = \frac{3}{4} + \frac{7}{5} + \frac{7}{5} = \frac{15 + 28 + 28}{20} = \frac{71}{20} = 3 \frac{11}{20}$

2)

$( \frac{1}{2} - \frac{1}{3} ) + ( \frac{1}{3} - \frac{1}{4} ) = \frac{3 - 2}{6} + \frac{4 - 3}{12} = \frac{1}{6} + \frac{1}{12} = \frac{2 + 1}{12} = \frac{3}{12} = \frac{1}{4}$

3)

$\frac{17}{51} + \frac{19}{57} - \frac{13}{39} = \frac{1}{3} + \frac{1}{3} - \frac{1}{3} = \frac{1 + 1 - 1}{3} = \frac{1}{3}$

4)

$\frac{2}{3} + 1 \frac{1}{2} - \frac{1}{4} = \frac{4 \times 2 + 3 \times 6 - 3}{12} = \frac{8 + 18 - 3}{12} = \frac{23}{12} = 1 \frac{11}{12}$

5)

$( \frac{3}{6} - \frac{1}{4} ) + ( \frac{1}{2} - \frac{1}{3} ) = (\frac{1}{2} - \frac{1}{4} ) + \frac{3 - 2}{6} = \frac{2 - 1}{4} + \frac{1}{6} = \frac{3 + 2}{12} = \frac{5}{12}$

6)

$(1 \frac{3}{5} - \frac{3}{10} ) + ( \frac{1}{4} - \frac{1}{8} ) = 1 \frac{3 \times 2 - 3}{10} + \frac{2 - 1}{8} = 1 \frac{3}{10} + \frac{1}{8} = 1 \frac{4 \times 3 + 5}{40} = 1 \frac{17}{40}$