Please help me with this word problem!

Answer:
[tex]f(g)=25g[/tex]
Step-by-step explanation:
Let [tex]g[/tex] be the number of gallons so [tex]f(g)[/tex] is the number of miles traveled per [tex]g[/tex] gallons.
We know for our problem that Brian's car gets 25 miles per gallon. Since the gallons is represented by [tex]g[/tex], his car will travel a total distance of 25g (where g is the number of gallons.
We also know that the total distance is given by [tex]f(g)[/tex], so we can put the two expressions together to get our function:
[tex]f(g)=25g[/tex]
Let's check:
- If he uses 1 gallon (g=1), so
[tex]f(1)=25(1)[/tex]
[tex]f(1)=25[/tex] miles
He will travel 25 miles with one gallon.
- If he uses 2 gallons (g=2), so
[tex]f(2)=25(2)[/tex]
[tex]f(2)=50[/tex]
He will travel 50 miles with two gallon.