Answer:
x = 4
Step-by-step explanation:
I don't see a picture, so I'm assuming that M, N, O are points on a line segment with endpoints M and O.
Point N bisects segment MO, so it's in the middle of that segment. That means the distance from M to N and the distance from N to O are equal.
7x - 15 = 2x + 5
5x - 15 = 5
5x = 20
x = 4
