Answer
$$x+2x^3y+3$$
Work Step by Step
In order to divide monomials, we look for common terms in the numerator and the denominator that can be canceled out. Doing this, we find:
$$\frac{5x^3y+10x^5y^2+15x^2y}{5x^2y} \\ \frac{5yx^2\left(x+2x^3y+3\right)}{5x^2y} \\ x+2x^3y+3$$
Note, if we wanted to check this answer, we could multiply the answer by the value we canceled out to see if that matched the original numerator.