"The cost of a phone call is 7 cents to connect and an additional 6 cents per minute (m)"
If "C" indicates the total cost of a phone call and "m" corresponds to the number of minutes the phone call lasted.
The phone call costs 7 cents to connect, this means that regardless of the duration of the call, you will always pay this fee. This value corresponds to the y-intercept of the equation.
Then, the phone call costs 6 cents per minute, you can express this as "6m"
The total cost of the call can be calculated by adding the cost per minute and the fixed cost: