Question

помогите пожалуйста умоляю ​

Answer 1

Ответ:

а) 4000; б) 50

Пошаговое объяснение:

а)

$\displaystyle\frac{{0{,}05}}{{\displaystyle\frac{1}{7} - 0{,}125}} + 5{,}2 = \displaystyle\frac{{\displaystyle\frac{1}{{20}}}}{{\displaystyle\frac{1}{7} - \displaystyle\frac{1}{8}}} + 5{,}2 = \displaystyle\frac{1}{{20}}:\displaystyle\frac{1}{{56}} + 5{,}2 = 2{,}8 + 5{,}2 = 8.$

Дальше можно рассуждать как о пропорции:

$0{,}2\,\% :8 = 100\,\% :x;\\\\x = \displaystyle\frac{{8 \cdot 100}}{{0{,}2}} = 4000.$

б)

$\displaystyle\frac{{4{,}6 - 2\displaystyle\frac{1}{3}}}{{4{,}6 + 2\displaystyle\frac{1}{3}}} \cdot 5{,}2 = \displaystyle\frac{{\displaystyle\frac{{23}}{5} - \displaystyle\frac{7}{3}}}{{\displaystyle\frac{{23}}{5} + \displaystyle\frac{7}{3}}} \cdot 5{,}2 = \displaystyle\frac{{69 - 35}}{{15}}:\displaystyle\frac{{69 + 35}}{{15}} \cdot 5{,}2 =$

$= \displaystyle\frac{{34}}{{15}} \cdot \displaystyle\frac{{15}}{{104}} \cdot 5{,}2 = \displaystyle\frac{{17}}{{52}} \cdot \displaystyle\frac{{52}}{{10}} = \displaystyle\frac{{17}}{{10}} = 1{,}7.$

$3{,}4\,\% :1{,}7 = 100\,\% :x;\\\\x = \displaystyle\frac{{1{,}7 \cdot 100}}{{3{,}4}} = 50.$