Answer:
the answer is: "Subtract 4 from 15. Then multiply the difference by 3."
Step-by-step explanation:
If there are 4 fewer blue pens in a box than black pens, and there are 15 black pens in each box, then that means there are 11 blue pens in each box.
So then, how many blue pens are in 3 boxes? There are 33 blue pens in 3 boxes, you can find this out by multiplying, 11 by 3.
the numerical answer is:
11 x 3 = 33
or, 3 x ( 15 - 4)
I hoped this helped!