ANSWER
m > 258.62 miles
Step-by-step explanation
Let the number of miles be m.
Company A has no initial fee but there is a charge of 79 cents ($0.79) per mile.
This means that after m miles, Company A's charge is:
0.79 * m = $0.79m
Company B has an initial fee of $75 and an additional charge of 50 cents ($0.50) per mile.
This means that after m miles, Company B's charge is:
75 + 0.50m
For company A to charge more than company B, then:
0.79m > 75 + 0.50m
Simplify and find m:
0.79m - 0.50m > 75
=> 0.29m > 75
Divide through by 0.29:
m > 75 / 0.29
m > 258.62 miles
That is the answer.