a store i roger's neighborhood sells boxes of pencils that have 3 in each box. roger bought several boxes of pencils athe store. which could be the number of pencils he bought?

21 is the number of pencils he bought

Step-by-step explanation:

c.

step-by-step explanation:

because first you have to add the 4x, 9x, and the 7x together and you get 20x and then you add the last numbers up and you get 5and then you put the subtraction sign in there and that's how you get the answer.