Multiple choice The roots of the equation $\displaystyle x^{3}+14x^{2}-84x-216=0$ are in AP GP HP none of these Reveal answer Fill a bubble to check yourself B Correct answer Explanation For the equation x^3 + 14x^2 - 84x - 216 = 0, testing for GP roots (a/r, a, ar) shows that the roots are 6, -2, -18. These form a GP with common ratio -3.