dy dx\frac{\;{\;\text{dy}\;}}{dx}dxdy = (5x + 1)4^{4}4 = 20(5x + 1)3^{3}3
let u = (5x + 1) = dudx\frac{\;du}{dx}dxdu = 5
y = u4^{4}4 then dydu\frac{\;dy}{du}dudy = 4u3^{3}3
Therefore, dydx= dydu× dudx\; \frac{dy}{dx} = \; \frac{dy}{du} \times \; \frac{du}{dx}dxdy=dudy×dxdu = 5 x 4u3^{3}3 = 20(5x + 1)3^{3}3
