Answer
$x^6-12x^5+60x^4-160x^3+240x^2-192x+64$
Work Step by Step
Apply Binomial Theorem.
$(a+b)^n=\sum_{r=0}^n\dbinom{n}{r}(a)^{n-r}b^r$
$(x-2)^6=\dbinom{6}{0}(x)^6(-2)^0+\dbinom{6}{1}(x)^5(-2)^1+\dbinom{6}{2}(x)^4(-2)^2+\dbinom{6}{3}(x)^3(-2)^3+\dbinom{6}{4}(x)^2(-2)^4+\dbinom{6}{5}(x)^1(-2)^5+\dbinom{6}{6}(x)^0(-2)^6$
or, $=x^6-12x^5+60x^4+(20x^3)(-8)+240x^2+6x(-32)+64$
or, $=x^6-12x^5+60x^4-160x^3+240x^2-192x+64$
