What is thw quadractic formula of this

Emily is entering a bicycle race for charity. her mother pledges $0.90 for every 0.75 mile she bikes. if emily bikes 18 miles, how much will her mother donate?

Joe has a rectangular chicken coop. the length of the coop is 4 feet less than twice the width. the area of the chicken coop is 510 square feet. what is the length of the chicken coup?

The cost of a taxi ride includes an initial charge of $2.00. if a 5km ride cost $6.00 and a 10km ride cost $10.00, determine the cost of a 15km ride.