DUe to lines A and B are parallel, measure of angle p is equal to the measure of angle (5x + 35), by these angles are alternate exterior.
Then, if x = 15, you have:
m∠p = (5x + 35)
m∠p = 5(15) + 35
m∠p = 75 + 35
m∠p = 110
Hence, the measure of angle p is 110°