Решебник по математике 6 класс Мерзляк ФГОС Задание 502

 

\[\boxed{\mathbf{502\ (502).}\mathbf{\ }Еуроки\ - \ ДЗ\ без\ мороки}\]

Пояснение.

Решение.

\[1)\ 13\% = \frac{13}{100}\]

\[52\ :\frac{13}{100} = 52 \cdot \frac{100}{13} =\]

\[= 4 \cdot 100 = 400\]

\[2)\ 80\% = \frac{80}{100} = \frac{8}{10} = \frac{4}{5}\]

\[\boxed{\mathbf{502.}\mathbf{\ }}\]

\[1)\ (x + 19,64) \cdot 0,18 = 14,4\]

\[x + 19,64 = 14,4\ :0,18\]

\[x + 19,64 = 1440\ :18\]

\[x + 19,64 = 80\]

\[x = 80 - 19,64\]

\[x = 60,36.\]

\[2)\ x\ :100 - 1,2367 = 2,9633\]

\[x\ :100 = 2,9633 + 1,2367\]

\[x\ :100 = 4,2\]

\[x = 4,2 \cdot 100\]

\[x = 4200.\]

\[3)\ 9\ :(7 - x) = 3,6\]

\[7 - x = 9\ :3,6\]

\[7 - x = 90\ :36\]

\[7 - x = 2,5\]

\[x = 7 - 2,5\]

\[x = 4,5.\]

\[4)\ b - 0,87b + 1,24 = 7,74\]

\[0,13b = 7,74 - 1,24\]

\[0,13b = 6,5\]

\[b = 6,5\ :0,13\]

\[b = 650\ :13\]

\[b = 50.\]