Question 1131994


{{{ (r-s)^5}}}

={{{ (r-s)(r-s)^2(r-s)^2}}}

={{{ (r-s)(r^2-2rs+s^2)(r^2-2rs+s^2)}}}

={{{ (r^3 - 3r^2*s + 3r*s^2 - s^3)(r^2-2rs+s^2)}}}

={{{ r^5 - 5r^4*s + 10r^3*s^2 - 10r^2*s^3 + 5r*s^4 - s^5}}}