Respuesta :
ANSWER:
The linear equation that models the cost of making a call lasting x mins is y = 0.2834x.
SOLUTION:
Given, when making a telephone call using a calling card, a call lasting 3 minutes costs $0.85.
we need write a linear equation that models the cost of making a call lasting x minutes.
Let y be the cost of making a call lasting "x" minutes using a calling card.
Then, y = cost of making call per minute [tex]\times[/tex] x minutes
Now, cost of making call per minute can be obtained from the case we have i.e. $0.85 per 3 minutes
Cost of call per minute = [tex]\frac{\text {total cost }}{\text {number of minutes}}[/tex]
Cost of call per minute = [tex]\frac{0.85}{3}[/tex]
Cost of call per minute = 0.2834
cost of call per minute is $0.2834 approximately
Now, y = 0.2834 × x
y = 0.2834x
hence, the linear equation that models the cost of making a call lasting x mins is y = 0.2834x.
