The linear equation used to solve the problem is t = 2 + 1.29a and total cost to download 30 songs is $ 40.7
Solution:
Given that music app charges $2 to download the app plus $1.29 per song downloaded
To find: write and solve a linear equation to find the total cost to download 30 songs
Let us first write a expression for total cost
Let "a" be the number of songs downloaded
So we can frame a equation as:
total cost = initial charge + cost of 1 song download x number of songs downloaded
total cost = 2 + 1.29a
If "t" represents the total cost, then the linear equation is:
t = 2 + 1.29a
finding the total cost to download 30 songs:
Here a = 30
Substitute a = 30 in above formula
total cost = 2 + 1.29(30)
total cost = 2 + 38.7
total cost = 40.7
Thus total cost to download 30 songs is $ 40.7