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:

$m=\frac{y_2-y_1}{x_2-x_1}$

$m=\frac{2.10-1.05}{2-1}$

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.