Taxi A charges a fee of $3.50, plus $1.75 per mile. Taxi B charges a few of $1.25, plus $2.00 per mile. At what distance would the taxi cost the same?

Taxi A
1mile £3.50+£1.75=£5.25
Taxi B
1mile £1.25+£2.00=£3.25

Taxi A
2miles £3.50+£3.50=£7.00
Taxi B
2miles £1.25+£4.00=£5.25

Taxi A
3miles £3.50+£5.25=£8.75
Taxi B
3miles £1.25+£6.00=£7.25

Taxi A
4miles £3.50+£7.00=£10.50
Taxi B
4miles £1.25+£8.00=£9.25

Taxi A
5miles £3.50+£8.75=£12.25
Taxi B
5miles £1.25+£10.00=£11.25

Taxi A
6miles £3.50+£10.50=£14.00
Taxi B
6miles £1.25+£12.00=£13.25

Taxi A
7miles £3.50+£12.25=£15.75
Taxi B
7miles £1.25+£14.00=£15.25

Taxi A
8miles £3.50+£14.00=£17.50
Taxi B
8miles £1.25+£16.00=£17.25

Taxi A
9miles £3.50+£15.75=£19.25 (the same)
Taxi B
9miles £1.25+£18.00=£19.25 (the same)

^^^
They would have to drive 9 miles for the taxi to cost the same.

Hope this helped, this is the longest way to work it out but also the simplest.