2x + y=1

5x-y=-15

2x y = 1

5x - y = -15

y = 1 - 2x

5x - (1 - 2x) = - 15

5x - 1 2x = -15

7x = -15 1

7x = - 14

x = -2

5 * (-2) - y = -15

-10 - y = -15

y = 5

Answer: (-2;5)