Let S 1
​
be the surface with equation x=2 y+1
​
and let S 2
​
be the sphere with equation x 2
+y 2
+z 2
−16x+6y−4z+76=0 1. Provide a hand-drawn sketch of the surface S 1
​
. Indicate proper rulings. 2. Determine the center and the radius of the sphere S 2
​
. 3. The x-intercept of surface S 1
​
and the center of sphere S 2
​
are endpoints of a diameter of another sphere S. Determine the equation (in center-radius form) of S.