Find the solution to the system of equations y=2x+3 y=-x

I’m stuck on this i don’t understand.

How can you solve an equation with a variable on both sides? complete the explanation. you can solve the equation by using *(blank)* operations to get the variable terms on one side of the equal sign and the constant terms on the *(blank)* side. then *(blank)* both sides by the coefficient of the resulting variable term.

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.