Which of the following descriptions of the carbon cycle is most accurate?

a. it is an open system because the amount of the carbon in the system stays constant.

b. it is an open system because the amount of carbon in the system is variable.

c. it is a closed system because the amount of carbon in the system stays constant.

he used the algebra tiles correctly.

step-by-step explanation:

given : 3x(2x-1)

solution :

since he used algebra tiles .

armando's solution is the same in the solution shown in figure

as he distributed 2x into x and x and wrote them vertically

and also write   -1 vertically

and 3x into x and x and x and wrote it horizontally

performing the multiplication in the algebra tiles we get

and solving the given expression :

3x(2x-1)

since solving the expression using tiles   and solving the expression algebraically we get the same answer

thus   we can choose the first statement as the answer to this problem which is "he used the algebra tiles correctly".

answer:

3 bags of apples and 2 bags of oranges.

step-by-step explanation:

21/58.

hope to be marked brainliest

9987

step-by-step explanation: