Tim is choosing between two cell phone plans that offer the same amount of free minutes. AT&T’s plan charges $39.99 per month with additional minutes costing $0.45 per minute. Verizon’s plan costs $44.99 with additional minutes at $0.40 per minute. How many additional minutes will it take for the two plans to cost the same?

39.99 + .45m = 44.99 + .40m

Subtract .40m and 39.99 from both sides to find m.