Answer:
dy/dx = -5y - y/x
Explanation:
In xy + 5x = 30
Differentiating xy implicitly
y + xdy/dx
Assuming u = xy
In xy = In u
Differentiating In u = 1/u = 1/xy
Differentiating 5x = 5 and differentiating a constant (30) = 0
1/xy(y + xdy/dx) + 5 = 0
(y + xdy/dx)/xy = -5
(y + xdy/dx) = -5xy
xdy/dx = -5xy - y
dy/dx = = (-5xy - y)/x
dy/dx = -5y - y/x