What does the constant term represent?

Henry places x marbles into an empty bucket.  Each marble has the same weight.  
The weight, in ounces, of the bucket and marbles can be calculated using the expression shown.

​3x + 8

What does the term 8 represent in this expression?
A.)  the weight of each marble
B.)  the weight of the empty bucket
C.)  the number of marbles in the bucket
D.)  the total weight of the bucket and marbles

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​Video Answer and Explanation:

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