Given: Equation of plane is 5y + 4 = 0

Formula Used: Equation of a plane is lx + my + nz = p where (l, m, n) are the direction cosines of the normal to the plane and (x, y, z) is a point on the plane and p is the distance of plane from origin.

Explanation:

Given equation is 5y = -4

Dividing by -5,

which is of the form lx + my + nz = p where l = 0, m = -1, n = 0

Therefore, direction cosines of the normal to the plane is (0, -1, 0)