To multiply these two binomials, we will use the F.O.I.L. method.
First-Outer-Inner-Last
First take the product of the first terms, which is 20x².
Then take the product of the outer terms which is 8x.
Then the product of the inner terms which is -20x.
Lastly take the product of the last terms which is -8.
Now let's combine like terms.
So our final answer is 20x^2 - 12x - 8.