Answer:
90xy³
Step-by-step explanation:
The least common multiple is the smallest multiple that a set of terms has in common.
To find the least common multiple, we factor the two monomials, then take the maximum power of each separate factor.
18xy² = 2 × 3² × x × y²
15y³ = 3 × 5 × y³
LCM = 2 × 3² × 5 × x × y³ = 90xy³
The least common multiple of the two expressions is 90xy³.