Answer
$$75y^2-45y$$
Work Step by Step
We know the following equation for the area of the shaded region:
$$ A_{shaded}=\text{Overall Area} - \text{ Area Not Shaded}$$
Using this, we find:
$$ A=(14y-5)(6y)-(3y(3y+5))\\ A=84y^2-30y-9y^2-15y\\ A=75y^2-45y$$