Equação do 2º grau

y= 2x²- 4x-30


a)= 2
b)= -4
c)= -30                                                          Delta= b²-4.ac
                                                                      Delta=16+240
                                                                      Delta= 256


             -b+ -4.ac
                 - ---------
                      2.a


            x¹= 4+240= 244 = 61

                   ------    ------
                    2.2        4

           x²=  4-240= - 236= -59
                   ------ =   -----
                      4           4


x= -b
     ----                                                 y=  -256         - 256= -32
                                                                  ------          ----
     2.a                                                        4.2               8

x= 4= 1                                                y= -32
    ----
    2.2