a.5 b.-3 c.5 d.7 e.8

suatu fungsi kuadrat f(x) dikatakan mempunyai akar 3 apabila kita memasukkanya ke f(x) harus = 0
x = 3
f(x) = x²-(3k+1)x+(8k-1)
f(3) = 0
0 = 3²-(3k+1)3+(8k-1)
0 = 9-9k-3+8k-1
0 = 9-3-1-9k+8k
0 = 5-k
k = 5

semoga membantu, mohon dikoreksi bila ada kesalahan