Explanation: First of all, your initial equation is wrong. It should be: cost = 30m + 150
To find how much 3 years will cost you have to first find how many months are in 3 years: 12 • 3 = 36 Then substitute 36 for m in the equation: cost = 30(36) + 150 Then solve: C = 30(36) + 150 C = 1080 + 150 C = 1230