nomor 12 tolong skrng

a=1 b=-6 c=-5
x1 + x2 = 6 dan x1 . x2 = -5
(2x1 + 1) + (2x2 + 1) = 2 (x1 + x2) + 2 = 12 + 2 = 14
(2x1 + 1) . (2x2 + 1) = 4x1.x2 + 2 (x1 + x2) + 1 = -20 +12 + 1 = -7

y = x^2 - 14x - 7
jawaban = c