Question

Помогите пожалуйста​​

Answer 1

Ответ:

$\frac{x + y}{x - y} - 10.7 = \frac{10(x + y) - 107(x - y)}{10(x - y)} = \frac{10x + 10y - 107x + 107y}{10x - 10y} = \frac{ - 97x + 117y}{10x - 10y} = \frac{ - 97 \times 3 + 117 \times 1.5}{10 \times 3 - 10 \times 1.5} = - \frac{77}{10} = - 7.7$