Answer:
D
Step-by-step explanation:
Number of chickens (c) is = 4 times number of horses (4h). c = 4h
R + g + b = 50
r = b + 6
g = b - 4
(b + 6) + (b - 4) + b = 50
3b + 2 = 50
3b = 50 - 2
3b = 48
b = 48/3
b = 16 <=== 16 blue marbles
r = b + 6
r = 16 + 6
r = 22 <=== 22 red marbles
g = b - 4
g = 16 - 4
g = 12 <=== 12 green marbles
negative number taken to an odd power gives a negative result (because, after cancelling, there will be one minus sign left over).