You can simplify polynomials by combining like terms. In mathematics, you are able to combine like terms but you cannot combine unlike terms. Terms are considered like terms if they have exactly the same variables with exactly the same exponents. A term can be a single number like 7 or -5.
Therefore for this problem, since both have terms of x:
7x+15x = 22x
I hope my answer has come to your help. God bless and have a nice day ahead!
