An online media service offers video and music downloads. Each download of a song costs $1.50. Each download of a video costs 2 times as much as the song download. You have a credit of $60. How many songs can you purchase after buying 15 videos?

10

Step-by-step explanation:

if a song costs $1.50 and a video is 2 times that amount of a song, then the video would cost $3. you have a balance of $60. you by 15 videos to start. i multiplied $3 by 15 to get the cost of the movies, witch is $45. after i got the cost of the movies i subtracted the $45 from the over all amount, i got 15. now to the songs. i have $15 to get music. 2 songs costs $3( 1.50+1.50= 3.00). 4 songs would cost $6. 8 songs would cost $12. after that i just added 1.50 until i hit a total of 15. so you can get 10 songs for $15

, and

for

step-by-step explanation:

we can analyze the pattern at which the terms increase. let us denote , , , so that we can call

note the following:

the pattern: to get the next term value, we just add the next term number (e.g. 1st, 2nd, to the previous term value (term values are the given numbers in the question, 1, 3, 6, 10, 15,

from , to get to , we add

from , to get to , we add

etc.

we need to form a recursive formula, a formula that has the next term as a function of the previous term. so a possible recursive formula can be

, and for

answer: b.36 feet

step-by-step explanation: