A.) 18
B.) 20
C.) 24
D.) 25

multiply by the conjugate

the conjugate is the bottom express (6-√13) with the middle changed to +

or (6+√13)

so times it be   (6+√13)/(6+√13)

$20 bought 16 songs

therefore each song costs $20/16 = $5/4 = $1.25

so:

2 songs would cost 2 * $1.25

3 songs would cost 3 * $1.25

songs would cost x * $1.25

since renata started with $20, then her balance (y) after buying x songs would be:

y = 20 - 1.25*x

well we can use $ left as the y axis and the amount songs purchased as the x axis.   first we are going to divide 20 by 16 to get 1.25 which means that each song is $1.25. *which means after 16 songs on the x axis the lone should be at the bottom at point (0, 0).*   your equation is y=20-1.25x if you need more information just let me know : )

the answer is 5.

by: nicholas