Question

Вычисли: 10/21-3/14,

Answer 1

Ответ и Пошаговое объяснение:

$\tt \dfrac{10}{21}-\dfrac{3}{14} = \dfrac{10 \cdot 2}{21 \cdot 2}-\dfrac{3 \cdot 3}{14 \cdot 3} =\dfrac{20}{42}-\dfrac{9}{42} =\dfrac{20-9}{42} =\dfrac{11}{42};$

$\tt \dfrac{5}{12}-\dfrac{3}{8} = \dfrac{5 \cdot 2}{12 \cdot 2}-\dfrac{3 \cdot 3}{8 \cdot 3} =\dfrac{10}{24}-\dfrac{9}{24} =\dfrac{10-9}{24} =\dfrac{1}{24};$

$\tt \dfrac{5}{9}+\dfrac{1}{4} = \dfrac{5 \cdot 4}{9 \cdot 4}+\dfrac{1 \cdot 9}{4 \cdot 9} =\dfrac{20}{36}+\dfrac{9}{36} =\dfrac{20+9}{36} =\dfrac{29}{36};$

$\tt \dfrac{1}{2}+\dfrac{1}{7} = \dfrac{1 \cdot 7}{2 \cdot 7}+\dfrac{1 \cdot 2}{7 \cdot 2} =\dfrac{7}{14}+\dfrac{2}{14} =\dfrac{7+2}{14} =\dfrac{9}{14};$

$\tt \dfrac{4}{9}-\dfrac{7}{18} = \dfrac{4 \cdot 2}{9 \cdot 2}-\dfrac{7}{18} =\dfrac{8}{18}-\dfrac{7}{18} =\dfrac{8-7}{18} =\dfrac{1}{18}.$