There are 2 methods of completing this problem: FOIL and double distribution. They both will come up with the same answer, and will show you both methods.
FOIL:
FOIL stands for First, Outer, Inner, and Last and they are the positions within the binomials. Here is how to do that:
Firsts - the 1st term of each binomial - x * x = x^2
Outer - the ones on the outside of the binomial group - x * -1 = -x
Inner - ther terms that are closest to the inside parenthesis - -2 * x = -2x
Lasts - The last term in each binomial - -2 * -1 = 2
Now add them together: x^2 -x - 2x + 2 = x^2 -3x + 2 (Final answer)
Double distribution:
(x - 2)(x - 1)
x(x - 1) - 2(x - 1) (Distribute the (x -1) across the 1st binomial
x^2 - x - 2x + 2 (Distribute again for each set of terms)
x^2 - 3x + 2 (Simplify)