A (8, 1) is your answer.
x + y = 9
x - y = 7
We have to use a system of equations to solve for both x and y
Take equation 1 (x + y = 9)
Solve for x by subtracting y from both sides
x = 9 - y
Plug 9 - y in for x in the second equation.
(9 - y) - y = 7
Solve for y
9 - 2y = 7
2 = 2y
y = 1
Now that we know y = 1, we can plug 1 in for y in the first equation to solve for x.
x + 1 = 9
Solve for x
x = 8
So our coordinate that satisfies the system of equations is (8, 1)