650 miles has to driven before the plans cost the same
When the two plans cost the same, the cost is $ 137.5
<em><u>Solution:</u></em>
Given that, Keisha can choose one of two plans
Let "n" be the number of miles driven
<em><u>For Keisha 1st Plan:</u></em>
The first plan has an initial fee of $40 and costs an additional $0.15 per mile driven
Therefore,
Cost of plan 1 = 40 + (0.15)n
<em><u>For Keisha 2nd plan:</u></em>
The second plan has an initial fee of $53 and costs an additional $0.13 per mile driven
Cost of plan 2 = 53 + (0.13)n
To find out the number of miles where the two plans cost the same set the two expressions equal to each other and solve for n
40 + 0.15n = 53 + 0.13n
0.15n - 0.13n = 53 - 40
0.02n = 13
n = 650
Thus 650 miles has to driven before the plans cost the same
Substitute 650 in any one of equations
40 + 0.15n = 40 + (0.15)(650) = 40 + 97.5 = 137.5
When the two plans cost the same, the cost is $ 137.5
