x equals 4 and y equals 5 . so the formula would be 5x+12y=80 and if we need 4 of the small boxes we sub x for 4 and we get 5(4) =20. Next, 80 minus 20 is 60, and the equation would now be 12y=60. we now divide both sides by 12 and we get left with y=5. 5x + 12y = 80 5(4) + 12(5)=80 20+60=80. That is all. I hope that doesn't sound confusing
