A phone plan costs $15 a month for up to 500 minutes of calls. Each min above 500 costs an additional $0.02.How much money do you have to pay for 600 min

Igot the answer of 15.8 years.

Period is the time it takes for one “cycle” to complete. in the parent sine function, period is 2*pi since sin(0) = 0, sin(pi/2) = 1, sin(pi) = 0, sin(3pi/2) = -1, and sin(2pi) = 0. at that point, the sequence repeats itself. i’m not sure if your graph is similar to the sine function since you didn’t provide a picture, but you can find the period by looking at a graph.

Basic algebra equation. first set up your equation: divide out 9.and now you are left with 2x + 4 = 8.