Can someone solve and explain this?

Basically all you have to do is find the area of both circle and then minus the non-shaded area from the shaded area. So the equation to find the area of a circle is πr^2 so the radius for the non-shaded shaded is 1.2 square that then mutiply it by π ,(pi). Next the radius for the whole circle is 3.5 so square that then mutiply it by π. Next just subtract the two, non-shaded to shaded area.

Answer is b ,-4x^2 - 13y^2