Answer:
x + 4y + z = 4
Explanation:
The standard equation is of the form, Ax + By + Cz = 0
The equation of the plane that passes through the point(-1, 1/2, 3) and is perpendicular to [1, 4, 1] is
A = 1, B = 4, C = 1
x = -1; y = 1/2; z = 3
A(x-(-1)) + B(y-1/2) + C(z-3) = 0
(x+1) + 4(y-1/2) + (z-3) = 0
(x+1) + (4y-2) + (z-3) = 0
x + 1 + 4y -2 + z -3 = 0
x + 4y + z - 4 = 0
x + 4y + z = 4