Multiply both sides by y...
(3/y)y-(6/y)y-2y
Simplify it...
(3/y)y=3
(6/y)y=6
3=6-2y
Subtract 6 from both sides...
-2y=-3
Divide both sides by -2...
y=3/2
The solution is y=3/2
Unfortunately, you haven't shared "the following points."
The equation of a circle centered at the origin and whose radius is 10 is
x^2 + y^2 = 10^2.
Your slope with the equation y = -x + 6 is m = -1
Do the volume of a circle then multiply by the length of the cylinder
area of a circle =

diameter/2 = radius
so 4^2 = 16 16*3.14 = 50.24
50.24*(4*3) = 50.24*12 = 602.88