Question

Виконайте дії, два приклада на фото​

Answer 1

Ответ:

1)

$\frac{9}{a + b} - \frac{4 - b}{a + b} = \\ = \frac{9 - (4 - b)}{a + b} = \\ = \frac{9 - 4 + b}{a + b} = \\ = \frac{5 + b}{a + b}$

2)

$\frac{a + 3}{a - 6} + \frac{a - 15}{a - 6} = \\ = \frac{a + 3 + (a - 15)}{a - 6} = \\ = \frac{a + 3 + a - 15}{a - 6} = \\ = \frac{2a - 12}{a - 6} = \\ = \frac{2(a - 6)}{a - 6} = 2$