It costs Linus a processing fee of $45 to set up a new cell phone account with AT&T plus $65 per month for the cell phone plan. His sister, Lucy, also wants to use the cell phone to call her friends each month. Lucy agrees to pay Linus $15 towards the processing fee and tells him she will pay $20 per month. Define a variable.

Write an expression that represents how much Linus will have to pay for the cell phone if Lucy contributes.

Determine how much Linus will pay if he has the cell phone for 6 months.