List numbers that have 24 as a multiple

What are the soultion(s) to the quadratic equation 40- x^2=0

Cassie is traveling 675 miles today to visit her brother and his family. so far, she has stopped for gas three times. at the first stop, she put in 7.1 gallons of gas and paid $23.79. at her second stop, she put in 5.8 gallons of gas and paid $19.08. and, at the third stop, 6.6 gallons and paid $20.39. at which stop did casey pay the most for gas?

The graph represents the gallons of water in a water tank with respect to the number of hours since it was completely filled