In addition to dog walking, on Tuesday Eric made $45 dog sitting at one of his customers homes. If he made $168 on Tuesday, write an equation to find the number of dogs he walked that day.

Activities done by Eric on Tuesday = Dog Walking and Dog Sitting

Money earned by Eric by dog sitting = $45

Let the number of dogs walked by Eric be = a

And money earned per dog walk = b

⇒ Total Money Earned = Money earned by dog walking + Money earned by dog sitting

⇒ 168 = 25 + a*b

⇒ 143 = a*b

Hence, the equation used to determine number of dogs walked is a*b=143, where a represents number of dogs walked and b represents money earned per dog walk.