Jenna is deciding between two cell-phone plans. The first plan has a $50 sign-up fee and costs $20 per month. The second plan has a $30 sign-up fee and costs $25 per month. What will the cost be after 4 months?
For the first plan, the cost after 4 months will be 4*$20 + $50 signup fee = $<<4*20+50=130>>130.
For the second plan, the cost after 4 months will be 4*$25 + $30 signup fee = $<<4*25+30=130>>130.
So the cost will be the same for both plans, at $130 after 4 months. Answer: \boxed{130}.