Respuesta :

Answer: After 2 hours of work. The amount will be $21

Step-by-step explanation:

Let h be the amount of hours.

Maryann has $9 saved (m=9) and can earn $6 per hour (6h)

Carlos has $3 saved (c=3) and can earn $9 per hour (9h)

If we add maryann's saved money and the money she can earn per hour and equal it to carlos's, we can calculate the amount of hours.

9+6h=3+9h

Start by subtracting 9

6h=3+9h-9

subtract 9h

6h-9h=3-9

combine like terms;

-3h=-6

divide by 3

h=-6/-3

h=2

To calculate the amount, plug this value into the equation.

9+6h=3+9h

9+6(2)=3+9(2)

3+18=3+18

21=21