Assume that r and s are particular integers a)Is 4rs even? b)Is 6r+4s2 + 3 odd? c) If r and s are both positive, is r2+2rs+s2 composite? Solution 1) yes 2) yes because 6r+4s^2 is even and when 3 is added it becomes odd 3) yes because it is (r+s)^2 it has r+s as factor.