D=b^2-4ac

D=11^2-4*4*(-3)=169

x1=1/4

x2=-3

a=4; b=11; c=3.                        D = b^2 - 4*a*c
                                                     X1 = (-b - кв. корень из D) / 2*a

                                                     X2 = (-b + кв. корень из D) / 2*a

D = 121 + 48 = 169

X1 = (-11 - 13) / 2*4 = 3
X2 = (-11 + 13) / 2*4 = 0.25

Ответ: X1=3; X2=0.25