Two ratios that have the same values are equivalent ratios determine whether the ratios are equivalent

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

Last one and the bottom answer choice is y=(x-4)^2+1 you guys!

The? half-life of a radioactive substance is 20 years. if you start with some amount of this? substance, what fraction will remain in 120 ? years