Question

Помогите. 20 балов реши систему уравнений

Answer 1

1/(x + y) + 1/(x - y) = 15  (1)

4/(x + y) + 1/(x - y) = 36 (2)

делаем (2) - (1)   4*(1) - (2)

3/(x + y) = 21

3/(x - y) = 24

1/(x+y) = 7

1/(x - y) = 8

x + y = 1/7

x - y = 1/8

2x = 1/7 + 1/8 = 15/56

x = 15/112

2y = 1/7 - 1/8 = 1/56

y = 1/112

ответ (15/112, 1/112)