Here's the equation for one year:
0.03(8000) + 8000
For four years:
4(0.03(8000)) + 8000
0.12(8000) + 8000
To make it simpler/smaller:
1.12(8000) = 8960
You can make 960 more dollars, and you now have $8960
The total cost of the cab ride was $25.50. The cabbie charges $1.50 per mile the entire trip.