Which Representation shows x as a function of x

If x + 10 = 70, what is x? a. 40 b. 50 c. 60 d. 70 e. 80

How do i do this activity, is appreciated

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.