If you would like to know a number you can square and the answer is bigger than 400 but smaller than 500, you can calculate this using the following step:
20^2 = 400 < 21^2 = 441 < 22^2 = 484 < 500
There are two correct results: 21 and 22.
Let
equals to amount charged for downloading individual songs

equals to amount charged for downloading an entire album.
Solve the system for

:


Solving the system for

is unoptional since we already have the answer we've been looking for. Your answer is

.
No because any two sides have to add up to be more than the third side
2+8 is more than 6
8+6 is more than 2 but
2+6=8 so these can't make a triangle