x^3+5=x^8
t^3 * t^3 = t^6
i guess it's u^6
g^2+4g+4
not sure abt (z-3)^3
expanding (z-3)^3
could it be: (z-3).(z+3)^2 ??
=>(z-3) (z^2+3z+9)
t^3 * t^3 = t^6
i guess it's u^6
g^2+4g+4
not sure abt (z-3)^3
expanding (z-3)^3
could it be: (z-3).(z+3)^2 ??
=>(z-3) (z^2+3z+9)
So (g+2)^2 is equal to g^2+4g+4, but it's also equal to (g+2).(g+2) [where I've used the dot for multiplication]
Does that help you for (z-3)^3 ??