Answer :
I don't know what $89.25 represents in the question but I can just assume that he saved that much more. "x" represents how much more he needs.
No, he doe not represent the equation correctly. "x" should not be on the right side of the equation.
Let "y" represent the total amount of the bicycle.
The correct equation should look like:
89.25 + 129.85 + x = y
Best of Luck!