Use implicit differentiation to find the derivative dy/ dx for each of the following cases:

(a) 7.(X^4) - X(Y^3) - 2(Y^5)=21

(b) ln( x^3. y) +(1/X.(Y^2)) +3.(Y^ 7) = 77

(c) e^(2.*y) . (x^2) +(y/x^6). ln(x) = 5*y