Expand the expression: $(1-2x)^5$
$\begin{array}{1 1} 1-10x+40x^2-80x^3+90x^4-32x^5 \\1+10x-40x^2+80x^3-90x^4+32x^5 \\1-10x+40x^2-80x^3+80x^4-32x^5 \\ 1+10x-40x^2-80x^3-90x^4+16x^5\end{array}$