How to solve an inverse operation that has two variables like this

This exercise has nothing to do with inverse operations.

Let L represent the number of lawns Tyler mows, and D the number of dogs he walks.

If he earns $20 for each lawn mown, then mowing L lawns earns him $20L. For example, if he mows 1 lawn, he gets $20. If he mows 2 lawns, he earns $40. And so on.

The same could be said about dog-walking. If he earns $15 for each walk, then walking D dogs is worth $15D. For example, if he walks 1 dog, he gets $15; for 2 dogs, $30; and so on.

If after a week he has earned a total of $260, then

20L + 15D = 260

which can optionally be simplified a bit by dividing through both sides by 5 to get

4L + 3D = 52

Since you mentioned "inverse", I suspect you interpreted the question as asking how many lawns Tyler mowed and how many dogs he walked. This is impossible, you cannot determine exactly how many lawns or dogs were involved. But there are only 4 ways this can happen, since L and D must be counting numbers.

D = 4, L = 10

D = 8, L = 7

D = 12, L = 4

D = 16, L = 1

the correct answer is 5

there are 70 more legs than eyes at the dog show (196 – 126 = 70). dogs have two more legs than eyes, and humans have the same number of legs as eyes. thus 70 is twice the number of dogs at the show, so the number of dogs is half of 70, which is 35. to get the number of humans, subtract 35 from 63: 63 – 35 = 28.

step-by-step explanation: