A car used 16 gallons of gasoline and traveled a total distance of 460 miles. The car's fuel efficiency is 30 miles per gallon on the highway and 25 miles per gallon in the city. How many gallons of gasoline were used on the highway.

12 gallons

Step-by-step explanation:

Total gallons = 16 gallons

Total distance = 460 miles

Fuel efficiency in the highway = 30 miles per gallon

Fuel efficiency in the city = 25 miles per gallon

Let

h = gallons of gasoline were used on the highway.

460 = 30h + 25(16 - h)

460 = 30h + 400 - 25h

460 - 400 = 30h - 25h

60 = 5h

h = 60/5

h = 12 gallons

12 gallons of gasoline were used on the highway.

{3 + i, 3 - i, 3, -1}

step-by-step explanation:

341

step-by-step explanation:

all you have to do is 9x31 (which equals 279) and then 20x31 (which equals 620). then you have to subtract. 620-279=341.