Answer:
[tex](x^{2} -6)^{2}[/tex]
Step-by-step explanation:
If you set [tex]x^{2} = z\\[/tex] then you can switch the equation to [tex]z^{2}-12z+36[/tex] which is easier to factor. Then we can factor normally:
[tex]-6*-6= 36\\-6+(-6)= 12\\[/tex]
[tex](z-6)(z-6)[/tex]
If we replace [tex]z[/tex] with [tex]x^{2}[/tex] then you get the answer as:
[tex](x^{2} -6)(x^{2} -6x)[/tex]
or
[tex](x^{2} -6)^{2}[/tex]
