PLEASE HELP WILL MARK BRAINLIEST!!

Jon and Keith save money at the end of each month and begin saving money at the same time. Jon's savings after m months are modeled with the formula f(m) = 40m + 20. Keith's savings after m months are modeled with the formula g(m) - 35m + 45. At the end of how many months will they have saved the same amount of money?​