Question

помогите пожалуйста ​

Answer 1

Ответ:

$-10\dfrac{27}{28}$

Пошаговое объяснение:

Вычислить

$-15\dfrac{1}{5} +\left|-2,5+4\dfrac{2}{7}\right |+\left|-12\dfrac{3}{4} +15,2\right|$

Найдем модули

$\left|-2,5+4\dfrac{2}{7} \right|=\left|4\dfrac{2}{7}-2\dfrac{1}{2} \right|=\left|4\dfrac{2}{7}^{\backslash2}-2\dfrac{1}{2}^{\backslash7} \right|=\left|2\dfrac{4-7}{14} \right|=\left|1\dfrac{14+4-7}{14} \right|=\\\\= \left|1\dfrac{11}{14} \right|=1\dfrac{11}{14}$

$\left|-12\dfrac{3}{4} +15,2\right|=\left|15\dfrac{1}{5} -12\dfrac{3}{4} \right|=\left|15\dfrac{1}{5}^{\backslash4} -12\dfrac{3}{4}^{\backslash5} \right|=\left|3\dfrac{4-15}{20} \right|=\left|2\dfrac{20+4-15}{20} \right|=\\\\=\left|2\dfrac{9}{20} \right|=2\dfrac{9}{20}$

$-15\dfrac{1}{5} +1\dfrac{11}{14} +2\dfrac{9}{20} =-15\dfrac{1}{5} +3\dfrac{110+63}{140} =-15\dfrac{1}{5} +3\dfrac{173}{140} =-15\dfrac{1}{5} +4\dfrac{33}{140} =\\\\=-\left( 15\dfrac{1}{5} -4\dfrac{33}{140}\right)=- 11\dfrac{28-33}{140} =-10 \dfrac{140+28-33}{140} =-10\dfrac{135}{140} =-10\dfrac{27}{28}$