Answer:
x=5/2 + a/2, y= 5/2 - a/2
Step-by-step explanation:
We can solve this system using addition of the equations
x+y=5
x-y=a
2x =(5+a)
x=(5+a)/2= 5/2 +a/2
x=5/2 +a/2
y = x - a , x=5/2 + a/2
y= 5/2 + a/2-a
y= 5/2 - a/2