Разложить на множители:

х²+4 х+1 =

D = 4^2 - 4*1*1 = 16-4 = 12

x1 = (-4+sqrt (12)) / 2 = (-4+2sqrt (3)) / 2 = - 2 + sqrt (3)

x2 = (-4-sqrt (12)) / 2 = (-4-2sqrt (3)) / 2 = - 2 - sqrt (3)

x^2+4x + 1 = (x - (-2+sqrt3)) * (x - (-2-sqrt3)) = (x + 2 - sqrt3) * (x + 2+sqrt3)