+128407 21. Rearrange as
x^4 + 27x^2 - 324 = 0 factor as
(x^2 - 9) ( x^2 + 36) = 0
(x + 3) ( x - 3) ( x + 6i) (x - 6i) = 0
Set each factor to 0 and solve for x and we get the solutions x = -3, 3, - 6i, 6i
22. ( s + 3v)^5 =
s^5 + 5*s^4*(3v) + 10*s^3*(3v)^2 + 10*s^2*(3v)^3 + 5*s*(3v)^4 + (3v)^5 =
s^5 + 15s^4v + 90s^3v^2 + 270s^2v^3 + 405sv^4 + 243v^5
