Answer:
$28.3
Explanation:
x=rate for 1km
y=initial fee
Mike: $35 for 15km -> 35 = 15x + y
Thomas: $24.50 for 10km -> 24.50 = 10x + y
Using those two equations we see the following:
Mike paid $10.5 more for 5 more km. The initial fee remains unchanged, so we can calculate the rate for 1km, which is 10.5/5=2.1.
35 = 15x + y
24.50 = 10x + y
10.5 = 5x
2.1=x
Using that value with one of the original equations we can calculate the initial fee.
35 = 15x + y
35 = 15*2.1 + y
35 = 31.5 + y
3.5 = y
Mike paid 15*2.1=31.5 ($2.1 for every km) plus the initial fee, his total was $35.
We subtract the 31.5 from the 35(total) and get the initial fee, which is $3.5.
Let's see what Lex will pay:
Km travelled times 2.1 (the rate for 1km) plus 3.5 (the initial fee).
12*2.1 + 3.5 = 28.3
Lex will pay $28.3 for the same taxi company to travel 12 km.