$87.00/5 is $17.4 dollars
45 of a number refers to 180, and 54 refers to 216. So 100 of a number is 400 and 1 of a number is 4. If 54x - 45x = 36, just plug in 4 and double check: 54(4) - 45(4) = 36 or 216 - 180 = 36, which is true.
If AB and CD are parallel lines and PR is the transversal, then angle PRD = angle APR by alternate interior angle theorem.
Angle PRD = 120 degrees so, 65 + x = 120 degrees
120 - 65 = 55 degrees