Answer:
The answer is B.)
Step-by-step explanation:
I counted the units!
X = the number of humans and y = the number of horses.
x+y=74
2x+4y=196
Because the number of humans and horses together is 74, and the total number of legs (2 per every human, x, and 4 per every horse, y) is 196. Then, just use elimination to solve.

So, now that you have y, you can plug it into the first equation to find x:

So, x = 50 and y = 24, so there are 50 humans and 24 horses.
The correct answer is B.
Let's say that the unknown value here is c. Although we are given two points on the line, it is only necessary to use one as there is only one unknown value, so let's say we choose the point (6, -12) and substitute this into the equation:
-12 = 1(6) - c
-12 - 6 = -c
-18 = -c
c = 18
Thus the equation for the line is y = 1x - 18