11 diminished by five times a number is the same as four times a number increased by 20 find the number

Pyotr tchaikovsky sporting goods operates on a 45% overhead based on the selling price, which results in an overhead of $65.34 on the newest version of an air hockey game set. if the air hockey game set costs pyotr tchaikovsky sports $49.32, find the selling price, the markup, and the net profit.

If x is 6, then 7x= a. 13 b. 42 c. 42x d. 76

What is the solution for 6 - 7/8? explain the steps.