The first thing we must do for this case is to define a variable: x: number of years y: total salary We have then: For first company: y = 1500x + 31000 For second company: y = 2000x + 28500 Equaling both equations we have: 1500x + 31000 = 2000x + 28500 Clearing x: 2000x - 1500x = 31000 - 28500 500x = 2500 x = 2500/500 x = 5 Answer: It will take for the salaries to be the same about: x = 5 years