ANSWER
(t² + 4)(t + 2)(t - 2)
EXPLANATION
To factor this expression we can use the difference of two squares:
[tex](t^4-16)[/tex]To see it more clearly, let's change the variable. Let x be t², then:
[tex]x^2=t^4[/tex]Replacing we have:
[tex](x^2-16)=(x+4)(x-4)[/tex]Replacing back x = t²:
[tex](t^4-16)=(t^2+4)(t^2-4)[/tex]Now we can use the difference of two squares one more time for the second parenthesis:
[tex](t^2+4)(t^2-4)=(t^2+4)(t^{}+2)(t^{}-2)[/tex]