Add the polynomials (xy+5x^2)+(xy-3y)+xy .

When we add or subtract polynomials, we have to find the
variables and exponents that match.

We'll remove the
brackets:

xy + 5x^2 + xy - 3y +
xy

Now, we'll verify if in the given expression there are
terms that have matching variables.

We'll combine the terms
that have the variables x*y:

xy + xy + xy =
3xy

We notice that the terms 5x^2 and - 3y do not have
matching variables, so we'll add them to the final
result.

The result of adding the polynomials
is:

(xy+5x^2)+(xy-3y)+xy = 3xy
+ 5x^2 - 3y