Question

помогите пж .............................​

Answer 1

Ответ:

Смотри решение на фото.......

Answer 2

1)

$\frac{3}{14x - 14y} - \frac{2}{21x - 21y} = \frac{3}{14(x - y)} - \frac{2}{21(x - y)} = \\ = \frac{3 \times 3 - 2 \times 2}{42(x - y)} = \frac{9 - 4}{42(x - y)} = \frac{5}{42x - 42y}$

2)

$\frac{2 - 3y}{ {y}^{2} - 9 } + \frac{5 - 2y}{y - 3} = \frac{2 - 3y}{(y - 3)(y + 3)} + \frac{5 - 2y}{y - 3} = \frac{2 - 3y + (5 - 2y)(y + 3)}{(y - 3)(y + 3)} = \\ = \frac{2 - 3y + 5y + 15 - 2 {y}^{2} - 6y }{(y - 3)(y + 3)} = \frac{ - 2 {y}^{2} - 4y + 17}{ {y}^{2} - 9 }$