Question

Пж помогите помогите помогите помогите дам 15 баллов

Answer 1

1) $4\dfrac{8}{15} - 6\dfrac{2}{3} : 1\dfrac{2}{3} = 4\dfrac{8}{15} - \dfrac{20}{3} : \dfrac{5}{3} = 4\dfrac{8}{15} - \dfrac{20\cdot 3}{3\cdot 5} = 4\dfrac{8}{15} - 4 = \boxed{\bf{\dfrac{8}{15}}}$

2)   $5\dfrac{3}{7} : \dfrac{19}{7} + 8\dfrac{5}{7} = \dfrac{38}{7} : \dfrac{19}{7} + 8\dfrac{5}{7} = \dfrac{38\cdot 7}{7\cdot 19} + 8\dfrac{5}{7} = 2 + 8\dfrac{5}{7} = \boxed{\bf{10\dfrac{5}{7}}}$

3)   $\left(3\dfrac{7}{8} - 2\dfrac{5}{6}\right) : 1\dfrac{1}{4} = \left(3\dfrac{21}{24} - 2\dfrac{20}{24}\right) : \dfrac{5}{4} = 1\dfrac{1}{24} : \dfrac{5}{4} = \dfrac{25}{24} : \dfrac{5}{4} = \dfrac{25\cdot 4}{24\cdot 5} = \boxed{\bf{\dfrac{5}{6}}}$

4)

  $\left(7\dfrac{5}{8} - 5\dfrac{3}{4}\right) : \dfrac{5}{14} = \left(7\dfrac{5}{8} - 5\dfrac{6}{8}\right) : \dfrac{5}{14} = 1\dfrac{7}{8} : \dfrac{5}{14} = \dfrac{15}{8} : \dfrac{5}{14} = \dfrac{15\cdot 14}{8\cdot 5} = \dfrac{21}{4} =\\\\\\= \boxed{\bf{5,25}}$