We have y = x + 2 and y = x+ 3.

Adding, using as a guide, we have:

(x + 2) + (x + 3)

 

We can remove the parentheses, so

x + 2 + x + 3

 

By Commutativity,
we can move the terms around to get

x + x + 2 + 3

or

2x + 5

 

So, y = 2x + 5