Question

Вычисли.
Cрооочно пжжжжжжж​

Answer 1

Ответ:

$1) \frac{10}{21} - \frac{3}{14} = \frac{11}{42} \\\\2) \frac{5}{12} - \frac{3}{8} = \frac{1}{24} \\\\3)\frac{5}{9} + \frac{1}{4} = \frac{29}{36}\\\\4)\frac{1}{2} + \frac{1}{7} = \frac{9}{14} \\\\5)\frac{4}{9} - \frac{7}{18} = \frac{1}{18}$

Пошаговое объяснение:

$1) \frac{10}{21} - \frac{3}{14} = \frac{10}{3*7} - \frac{3}{2*7} = \frac{2*10}{2*3*7} - \frac{3*3}{2*3*7} = \frac{20}{42} - \frac{9}{42} = \frac{11}{42} \\\\2) \frac{5}{12} - \frac{3}{8} = \frac{5}{2*2*3} - \frac{3}{2*2*2} = \frac{2*5}{24} - \frac{3*3}{24} = \frac{10}{42} - \frac{9}{42} = \frac{1}{24} \\\\3)\frac{5}{9} + \frac{1}{4} = \frac{4*5}{4*9} + \frac{9*1}{4*9} = \frac{20}{36} +\frac{9}{36} = \frac{29}{36}$

$4)\frac{1}{2} + \frac{1}{7} = \frac{7*1}{2*7} + \frac{2*1}{2*7} = \frac{7}{14} + \frac{2}{14} = \frac{9}{14} \\\\5)\frac{4}{9} - \frac{7}{18} = \frac{2*4}{2*9} - \frac{7}{18} = \frac{8}{18} - \frac{7}{18} = \frac{1}{18}$