432

a)
$\left(x^2-1\right)\left(x^2+1\right)$
$laskukaava\ \left(a+b\right)\left(a-b\right)=a^2-b^2$

$\left(x^2\right)^2-1^2=x^4-1$

b)

$\left(2x^3+1\right)^2$
$laskukaava\ \left(a+b\right)^2=a^2+2ab+b^2$
$\left(2x^3\right)^2+4x^3+1^2=4x^6+4x^3+1$

c)

$\left(x^4-1\right)^2$
$laskukaava\ \left(a-b\right)^2=a^2-2ab+b^2$
$\left(x^4\right)^2-2x^4+1^2=x^8-2x^4+1$