p = 12x is the function rule to calculate the total number of pens when you know the number of boxes
<em><u>Solution:</u></em>
Given that,
Pen are shipped to the office supply store in boxes of 12 each
To find: Write a function rule to calculate the total number of pens when you know the number of boxes
Let "p" be the total number of pens
Let "x" be the number of boxes
Number of pens in each box = 12
Then from given information,
Total number of pens = Number of boxes multiplied by number of pens in each box
Thus the function rule is found