Let f(x)=(1x^4-18)^3 and g(x)=1x^4-18. Given that f(x)=(h*g)(x), Find h(x)

Afamily has two cars. the first car has a fuel efficiency of 25 miles per gallon of gas and the second has a fuel efficiency of 15 miles per gallon of gas. during one particular week, the two cars went a combined total of 1025 miles, for a total gas consumption of 55 gallons. how many gallons were consumed by each of the two cars that week?