Find the maximum value of f(x,y) - 28-x²-y2 on the line x + 5y = 26. The maximum value of fix.y)-28-x2-y2 on the line x + 5y-26 is (Simplify your answer.) Find the volume of the region cut from the solid elliptical cylinder x² + 16y2 s 16 by the xy-plane and the plane z-x+4 The volume is (Type an exact answer in terms of x.) Integrate fix.y.z)=(x+y+z)/(x² + y² +2²) over the path r(t) = 3t 1+3tj+2tk. 0