no 21, 22 tolong dengan caranya ya

21. f(x) = px^3 - 2x^2 + x + 3p
f(3) = 27p - 18 + 3 + 3p = 5
30p = 20
p = 20/30 = 2/3(c)

22. f(x) = -2x^5 + 2px^3 - qx^2 + 3
f(-1) = 2 - 2p - q + 3 = 3
2p + q = 2...(1)
f(2) = -64 + 16p - 4q + 3 = -21
4p - q = 10...(2)

(1) + (2)
6p = 12
p = 2, q = -2

p^2 + 2pq + q^2 = 0(c)

p.s: kalo betul, plis jawaban terbrainly nya ya