Odgovor:
# x = (9 + -sqrt177) / - 16 #
Pojasnilo:
Poenostavite vzorec korak za korakom
#y = - (2x-1) ^ 2-4x ^ 2-13x + 4 #
#y = - (4x ^ 2-4x + 1) -4x ^ 2-13x + 4 #
# y = -8x ^ 2-9x + 3 #
Z uporabo kvadratne formule
# x = (9 + -sqrt (81 + 4 * 8 * 3)) / - 16
# x = (9 + -sqrt177) / - 16 #