See the answer upstairs for this question, and I was bypassed.

But I think so.

First of all, I think x y of classmate A directly represents the number of boxes A and B.

Box A consists of four rectangles and 1 square.

The box consists of three rectangles and two squares.

X+2y= 140 means that 140 squares can form a box X and a box B with 2y squares.

4x+3y=360 means that 360 rectangles can form box A 4x and box B 3y.

According to formula a, x is the number of boxes a and y is the number of boxes B.

As for student B's formula 4x+3y/2=360.

8x+3y=720 A box consisting of 8 x's and 3 y's uses much more X than Y, so the number of X's should be more than Y 's..

This usage should be that x is the number of rectangular cardboard and y is the number of square cardboard.

As for why it is 3y/2, I haven't figured it out either.