Answer:
y=x-2
Explanation:
9 is 2 less than 7
if you just do y=x, when the line hits 9 on the x-axis, it is 2 units to high on the coordinate plane. So if you subtract 2, it hits the point.
on the graph below, the green line is y=x and the red one is y=x-2
(the blue point is (9, 7))