When given a system of equations in​ slope-intercept form, is graphing or substitution the most efficient method to​ solve? Explain.

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?

Does anyone know how to solve and graph this: 4 + | a + 2 | < 7the only part i don't get is the "4 +"

10 points? me . its important ‼️‼️