Respuesta :

3(1x4)12+9(3+2)-6
I hope this helps you
there are 3 pens per box.

lets say that pens = x and boxes = y

if you are trying to find the number of pens based on how many boxes there are, the equation could be x = 3y

if you are trying to find the number of boxes based on how many pens there are, the equation could be y = x/3

either could work i believe!