Lexi received a $45 gift card to download music on her mp3 player. each song costs $1.50. the amount left on the gift card is a function of the number of songs purchased. what is the domain and range?

The domain goes from 0 to 30

The range is from 0 to 45

Step-by-step explanation:

The amount left can be modeled by a first order function in the following format:

In which is her amount left, is her initial amount, n is the number of songs bought and p is the price of each song.

The problem states that Lexi received a $45 gift card. So her initial amount is 45. Each song costs $1.50, so . So, the function for the amount left on the gift card is:

The range are the values that Lexi can have left. So the range is from 0 to 45.

The domain is the number of musics she can buy. So, the smallest value in the domain is 0. The biggest is the value of n for which . So:

The domain goes from 0 to 30

150.6

all i did was i multiplied 5.02 by 30

hello from mrbilldoesmath!

answer:

(7 x + 6 y) (49 x^2 - 42 x y + 36 y^2)

discussion:

the trick is to recognize that 343 = 7^3 and 216 = 6^3 and, in general,

a^3 + b^3 =   (a + b) (a^2 - a b + b^2).

in our case

343x^3+216y^3   =   (7x)^3 + (6y)^3

so take a = 7x and b = 6y in the above equation to get the answer.

you,

mrb