Hi Timothy,
1.Which explains why the sequence 216, 12, 2/3 is arithmetic or geometric?
Answer - C.The sequence is geometric because it decreases by a factor of 1/18
The reason I chose C is the fact that the numbers go down greatly, and it has to to be geometric because when you are trying to solve the problem with arithmetic you don't get and exact rule for how to solve the problem.
Step-by-step explanation:

Answer:
x=9, y=3
Step-by-step explanation:
-4x+6y=-18
y=-2x+21
-4x+6(-2x+21)=-18
-4x-12x+126=-18
144=16x
x=9
y=-2x+21
y=-18+21
y=3
Answer:
He planted a total of 42 carrots between the 2 gardens
Step-by-step explanation:
3 x 7 = 21
21 x 2 = 42