Question

срочно!! в течении 10 минут ответ нужен​

Answer 1

Решение:

$a)~~\dfrac{12}{23} - \dfrac{8}{23}+\dfrac{5}{23} = \dfrac{12-8+5}{23}= \dfrac{9}{23}.$

$b)~~8\dfrac{7}{9} + \Big (7\dfrac{5}{9}-4\dfrac{4}{9}\Big) = \\ \\=8\dfrac{7}{9} + 7\dfrac{5}{9}-4\dfrac{4}{9} = (8+7-4)+\Big ( \dfrac{7+5-4}{9}\Big )= \\\\=11\dfrac{8}{9}.$

$c)~~ 11\dfrac{2}{19} - \Big (3\dfrac{17}{19}+6\dfrac{14}{19}\Big) = \\ \\=11\dfrac{2}{19} - 3\dfrac{17}{19}-6\dfrac{14}{19}= (11-3-6)+\Big ( \dfrac{2-17-14}{19}\Big )= \\\\=2-\dfrac{29}{19}=2 - 1\dfrac{10}{19} = 1\dfrac{19}{19}-1\dfrac{10}{19}=\\\\ = \dfrac{9}{19} .$