Respuesta :

ulili

Answer:

(3, 12)

Step-by-step explanation:

x + y = 15

x - y = -9

add them together

2x + 0y = 6

2x = 6

x = 6/2

x = 3

substitute 3 into any equation, i chose x + y = 15

3 + y = 15

y = 12

check for 2nd equation:

3 - 12 = -9

-9 = -9