Let the variables be d and c. Then d= 2c-5.
Adding 3 more dogs and 3 more cats, we get d+3 = 2(c+3) - 5
Using the given ratio:
c+3 3
------ = ----- which leads to 4c+12 = 3d+9. Since d=2c-5, subst. 2c-5 for
d+3 4 d in this second equation:
4c + 12 = 3(2c-5) + 9
Then: 3 = 2c - 15, or 18 = 2c, or c = 9.
If c = 9, then the # of dogs is d = 2c - 5, or 2(9)-5, or 13.
There are 9 cats and 13 dogs.
Could this have been 15 cats and 20 dogs originally? This ratio is 3/4.
However, if we add 3 to 15 and 3 to 20, we get 18 and 23, which is not in the ratio 3 to 4. NO.
