Problem 5
x = number of songs downloaded
MyTunes charges $2.50 per song, so you pay 2.50*x dollars if you download x songs. If M is the cost of using MyTunes, then M = 2.50*x.
Let G be the cost of using Great Songs. The equation here is G = 1.50*x+50. We have 1.50*x representing the cost of downloading x songs (at 1.50 dollars a piece) plus the membership fee of $50. So the total cost here is 1.50x+50 dollars.
We want to find out when Great Songs is a better deal, so we want to determine what x values make G smaller than M
(Great Songs Cost) < (MyTunes Cost)
G < M
1.50x+50 < M ................................... replace G with 1.50x+50
1.50x+50 < 2.50x ............................. replace M with 2.50x
1.50x+50-1.50x < 2.50x-1.50x ....... subtract 1.50x from both sides
50 < 1.00x
50 < x
x > 50
If you download more than 50 songs, then Great Songs will be the better deal since it will be the cheaper plan.