Mandy earned x dollars and Andy earned 4x �+ 7 dollars on the first day of a charity carwash. If Mandy and Andy each earned the same amounts on the second and third days of the car wash, how much did they earn together over the course of the 3 days?
together on the first day they earned x + 4x+7 = 5x +7
they did this for 3 days,
so what is 3(5x+7) ?