Question

9•(2у-1 1/10)-7•(3у+2 1/10)=25,5
Пожалуйста помогите решить

Answer 1

$9(2y - \frac{1}{10} ) - 7(3y +2 \frac{1}{10} ) = 25.5 \\ 9 \times 2 = 18 \: \: \: \: \: 9 \times 1 = 9$

$18y - \frac{9}{10} - 7(3y + \frac{21}{10} ) = 25.5 \\ 7 \times 3 = 21 \: \: \: \: 7 \times 21 = 147$

$18y - \frac{9}{10} - 21y - \frac{147}{10} = 25.5 \\ 21 - 18 = 3 \: \: \: \:$

$- 3y - \frac{78}{5} = 25.5 \\ - 3y = 25.5 + \frac{78}{5} \\ 25.5 \times 2 = 21$

$- 3y = \frac{51}{2} + \frac{78}{5} \\ - 3y = \frac{411}{10}$

$y = - \frac{137}{10} \: \: y = - 13 \frac{7}{10} \: \: y = - 13.7$