Answer:
p = 11, I hope this helps and I hope you can improve your grade.
Explanation:
Adjacent Angles = 90 degrees, or a right angle.
90 = (5p + 7) + (3p - 5)
1. Subtract the numbers
90 = 5p + 2 + 3p
2. Combine Like Terms
90 = 5p + 2 + 3p
90 = 8p + 2
3. Subtract 2 from both sides
90 - 2 = 8p + 2 - 2
88 = 8p
4. Divided 8 from both sides
88/8 = 8p/8
p = 11