[tex]w+w+w+w+w+15-7=\underbrace{w+w+w+w+w}_5+(15-7)\\\\=5w+8-\text{finish}\\\\\text{You can not add 5w and 8. These are different monomials.}[/tex]
Example:
5w - five apples
8 - eight strawberries
5w + 8 = (five apples) + (eight strawberries) = 13 of what?
You can add only numbers of the same fruits.
