12+9 over three to the second power

What are “like terms”? why can we only add like terms?

It says factor each expression completely 8y+48

In the diagram, points d and e are marked by drawing arcs of equal size centered at b such that the arcs intersect ba and bc. then, intersecting arcs of equal size are drawn centered at points d and e. point p is located at the intersection of these arcs. based on this construction, m , and m