Please explain how to do this and do them for me i will give brainliest

Suzanne began a trip with 18 1/2 gallons of gas in the gas tank of her car if she hughes 17 3/4 gallons on the trip how many gallons does she have left once she finish the trip

Use the quadratic function to predict f(x) if x equals 8. f(x) = 25x2 − 28x + 585

Convert the density of surface sea water to metric tons/cubic meter