Question

LaShawn wants to buy some music online. There are two plans to choose from. The first plan is a flat rate of $1.29 per download. The second plan has a membership fee of $21 and the fee of $.99 per download. Let x be the number of downloads and C be the cost whem are the costs of the twp planes equal to each other?

Answer 1

1.29x=21+.99x
You want them to become equal, and you can get that if you get x by itself.
.3x=21
21/.3= 70= x
So at 70 downloads, they'll be the same. We can check to see if we're right.
1.29 ×70=90.3
21 + 69.3 = 90.3
So they'll be the same at 70 downloads, and they'll cost $90.30.