28x²-5x-30=0Помогите решить.

Question

28x²-5x-30=0
Помогите решить.

Answer 1

28x^2 - 5x - 30 = 0
D = b^2 - 4ac = (-5)^2 - 4*28*(-30) = 25 + 3360 = 3385
VD = V3385
           5 + V3385              5 - V3385
x1 = --------------------- = ----------------------------
              2*28                         56
          5 - V3385                  5 - V3385
x2 = -------------------------- = -----------------------
               2*28                           56