Can someone help please?

Josephine has a great garden with and area of 2x2 + x - 6 square feet

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?

Simply 8x squared + 5(7x squared- x) - 2x =