Answer:
Dan needs to walk dogs for at least 9 hours in order to earn more than $520 a week.
Step-by-step explanation:
Since his car wash attendant job pays $400 a week then you can subtract that from your final revenue.
$520-$400=$120
Now, to find out how many hours he has to walk dogs for in order to earn more than $520, you need to know some basic multiplication so...
$15×8=$120
...but he needs to earn MORE than $520 so...
$15×9=$135
$400+$135=$535.