Final answer:
A system of equations to determine the number of hours Ivon worked mowing lawns and washing dogs can be written as 13m + 12d = $124 for the total earnings and m + d = 10 for the total hours worked.
Step-by-step explanation:
To determine the number of hours Ivon worked mowing lawns (m) and washing dogs (d), we can set up two equations based on the information provided.
Since Ivon makes $13 per hour mowing lawns and $12 per hour washing dogs, we have the following equation for his earnings:
13m + 12d = $124
We also know that Ivon worked a total of 10 hours last week, which gives us a second equation:
m + d = 10
These two equations together form a system of linear equations that can be solved to find the values of m and d, representing the hours spent mowing lawns and washing dogs, respectively.