no 15 Ada yang bisa Bantu Cari jwban dan jalannya

x2 + 6x + 2 = 0
a = 1 b=6 c=2

x1.x2 = c/a = 2/1 = 2
x1+x2 = -b/a = -6/1 = -6

x1^2 + x2^2 - 6x1x2 = ((x1 + x2)^2 - 2x1x2) - 6x1x2 = ((-6)^2 - 2.2) - 6.2 = 32 - 12 = 20
Maaf kalau salah :)