Question

Solve the question on the picture if it is wrong

Answer 1

Given:

Cost of 1 digital song = $1.05

Cost of 2 digital song = $2.10

Cost of 5 digital song = $5.25

To find:

The equation and the cost of 25 downloaded digital songs.

Solution:

Let us take two points (1, 1.05) and (2, 2.10).

Here
`x_1=1, y_1=1.05, x_2=2, y_2=2.10`

Slope:

`$m=(y_2-y_1)/(x_2-x_1)`

`$m=(2.10-1.05)/(2-1)`

m = 1.05

Using point-slope formula:

`y-y_1=m(x-x_1)`

`y-1.05=1.05(x-1)`

`y-1.05=1.05x-1.05`

Add 1.05 on both sides, we get

`y=1.05x`

Here x is the independent variable and c is the dependent variable.

So that substitute x = n and y = c.

`c=1.05n`

The equation is c = 1.05 n.

Substitute n = 25 in the equation.

`c=1.05(25)`

`c=26.25`

The cost of 25 songs is $26.25.