i dont understand these equations and notation

Question

Given the following equations what is the corresponding Θ(x^? ) notation
((2x-2)(2x+4))/8
((2x^2-2x+2)(2x+4))/2
((3x^3+2x^2+4x+2)(2x^2+3x+2))/12

Answer 1

I believe in Θ(x^? ) , the ? is basically just the highest power of x that exists once the equation is simplified.

So, that would be

 

2

3

5