Answer: 15 goats
Explanation:
h = hens - they have 2 legs
g = goats - they have 4 legs
The equations would be:
h + g = 19
2h + 4g = 68
To solve this, I personally prefer substitution, we're isolating h since we need to find g:
h + g = 19
h = 19 - g
Now that we have h, we can plug this into the second equation:
2h + 4g = 68
2(19 - g) + 4g = 68
38 - 2g + 4g = 68
2g = 30
g = 15
There are 15 goats.
Adding onto this, 19 - 15 = 4, so there are 4 hens.