Solution: 6.5025 dollars.
Analysis:
We have a speed of Bobby, and the time he used to go to work. With these values, we can find the distance in miles:
[tex]\begin{gathered} Distance=Speed\ast Time \\ Distance=45\frac{miles}{hour}\ast1.25hour \\ Distance=56.25\text{ }miles \end{gathered}[/tex]If we know the distance and how many miles travel per gallon, we can find how many gallons need Bobby to go to work:
[tex]\begin{gathered} Amount\text{ }of\text{ }gallons=\frac{Distance}{Relationship\text{ }milespergallon} \\ \\ Amount\text{ }of\text{ }gallons=\frac{56.25miles}{25\frac{miles}{gallon}} \\ \\ Amount\text{ of }gallons=2.25\text{ }gallons \end{gathered}[/tex]After we find the amount of gallons used, we can fin how much many money does Bobby spend:
[tex]\begin{gathered} Money=Gallons\ast Cost\text{ }per\text{ }gallon \\ Money=2.25\ast2.89 \\ Money=6.5025\text{ }dollars \end{gathered}[/tex]