Multiply: Try to recognize the type of product to be multiplying.
(x-4x^3)^2
Hint: use (a + b)^2 = a^2 + 2ab + b^2
Here is an example to help you.
(x^2 + 1)^2
(x^2)^2 + 2(x^2)(1) + 1^2
= x^4 + 2x^2 + 1
(x-4x^3)^2
Here is an example to help you.
(x^2 + 1)^2
(x^2)^2 + 2(x^2)(1) + 1^2
= x^4 + 2x^2 + 1