Let's assume
she drives 'x' miles
we are given
The initial fee is $39.99 for the car
it costs $0.20 per mile
so, we can find total cost
total cost =39.99+0.20*x
we are given final bill is $100
so, we can set it equal
[tex] 100=39.99+0.20x [/tex]
now, we can solve for x
[tex] 100-39.99=0.20x [/tex]
[tex] 0.2x=60.01 [/tex]
[tex] x=300.05mile [/tex]
so,
she drives 300.05 miles..........Answer