Find the volume of revolution by rotating the region y=16-x, y=3x+12, and x=-1, about the x-axis using the disk or washer method.
Let's take the I don't know what method (say hollow disk).
Your hollow disks will have an area of *and an heigth of [tex]*dx [tex]
You must find the intersection to know your bound of integration.
[tex] 16-x = 3x+12 \implies 1 \geq x \geq -1[tex]