Each figure represents a number, box = 1, circle =2, triangle =5.

The graph contains the representative "+",and the graph is inscribed with the representative "-"

Can be listed in sequence: box+circle = 1+2=3.

Circle-box =2- 1= 1

Box+triangle = 1+5=6

Triangular box =5- 1=4

Triangle+circle =5+2=7