We have to factor a^4 - b^16

we use x^2 - y^2 = (x +y)(x - y)

a^4 - b^16

=> (a^2 - b^8)(a^2 + b^8)

=> (a - b^4)(a + b^4)(a^2 + b^8)

**Therefore a^4 - b^16 = (a - b^4)(a + b^4)(a^2 + b^8)**

We have to factor a^4 - b^16

we use x^2 - y^2 = (x +y)(x - y)

a^4 - b^16

=> (a^2 - b^8)(a^2 + b^8)

=> (a - b^4)(a + b^4)(a^2 + b^8)

**Therefore a^4 - b^16 = (a - b^4)(a + b^4)(a^2 + b^8)**