Answer
$$2u^2v+3u^2+3uv^2+uv$$
Work Step by Step
We simplify the expression by combining like terms. Like terms must (1) be raised to the same power and (2) consist of the same variable (i.e. x and y are not like terms). It is also important to note that numbers are all like terms with each other when not multiplied by anything. Thus, combining like terms, we obtain:
$$ 2u^2v-uv^2+uv+3u^2-v^2u+5uv^2 \\ 2u^2v+3u^2-uv^2-uv^2+5uv^2+uv \\ 2u^2v+3u^2+3uv^2+uv$$