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Question

Mandy earned x dollars and Andy earned 4x + 7 dollars on the first day of the carwash. Of Mandy and Andy earned the same amounts on the second and third days of the car wash, how much did they earn together over the course of 3 days.

Answer 1

For day one, the total appears to be 5x+7 (I trust that you see why).

 

If the same thing happened on two additional days, you should multiply the prior day's total expression by 3.

 

Of course we don't get a numerical value of $, just an expression.