How do i solve this algebra equation x+7=2x-8

Which of the following lines is not parallel to the graph of y = 4x +7?

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.

Can someone me and explain..will award brainlest!