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Ryan earns $5 for each small dog he walks and $8 for each large dog he walks. Today he walked 8 dogs and made a total of $55. How many small dogs did Ryan walk?

Ryan walked _____ small dogs.

User Bribou
by
7.9k points

2 Answers

4 votes
s= small dogs and l= large dogs

s + l = 85s + 8l = 55

multiply the first equation by an amount that will get rid of a variable.
-5s - 5l = -405s + 8l = 55

Now divide both sides by 3
3l = 15l = 5

s + 5 = 8s = 3


Now let's make sure that we got the right answer:

5 * 3 + 8 * 5 = 5515 + 40 = 5555 = 55


We are correct!

Ryan walked 3 small dogs

I hope this helps!
User Pockets
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7.1k points
3 votes
Let L and S be the number of large and small dogs respectively.

L+S=8 so we can say L=8-S

5S+8L=55, using L found above in this equation yields:

5S+8(8-S)=55

5S+64-8S=55

-3S+64=55

-3S=-9

S=3, since L=8-S

L=5

So Ryan walked 3 small dogs and 5 large dogs.
User John Vottero
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7.2k points