Question

como resolver este sistema:

x+y = 5
x-y =9

Answer 1

x+y=5
x=5-y

x-y=9
(5-y)-y=9
5-2y=9
-2y=9-5
-2y=4
y=-4/2
y=-2

x=5-(-2)
x=5+2
x=7

Answer 2

$2x = 14 \\ x = \frac{14}{2 } \\ x = 7 \\ \\ 7 - y = 9 \\ - y = 9 - 7.( - 1) \\ y = - 9 + 7 \\ y = - 2$