Answer
We simplify the expression to:
$$15x + 40y$$
Work Step by Step
To simplify this expression, we use the order of operations.
First, we use the distributive property:
$$15x + 10y + 6(5y)$$
Next, we do the multiplication:
$$15x + 10y + 30y$$
Finally, we combine like terms:
$$15x + 40y$$
