Let, y = x ^{– 4} (3 – 4x ^{– 5})

We have to find dy/dx

As we can observe that y is a product of two functions say u and v where,

u = x ^{– 4} and v = 3 – 4x ^{– 5}

∴ y = uv

As we know that to find the derivative of product of two function we apply product rule of differentiation.

By product rule, we have –

…equation 1

As, u = x ^{– 4}

∴ …equation 2 {∵ }

As, v = 3 – 4x ^{– 5}

…equation 3 {∵ }

∴ from equation 1, we can find dy/dx

∴

⇒ {using equation 2 & 3}

⇒

Hence,