Question

PORFA ESTAS ECUACIONES POR FACTORIZACIÓN:'C
A) -3x²+20=0
B) -8x-15x²=0
C). x²-12x-69=0

EXPLICADAS PORFA GRACIAAAS:(

Answer 1

A)
       - 3x^2 + 20 = 0
        - (x^2 - 20) = 0
            x^2 = 20 =
               x = √20
                  = +/- 2√5
                                        x1 = - 2√5
                                        x2 = 2√5
                                                             S = {- 2√5, 2√5}
B)
     ordenando
        - 15x^2 - 8x = 0

factorizando
        - x(15x + 8) = 0

cada factor debe ser nulo
                      - x = 0
                                         x1 = 0
              15x + 8 = 0
                    15x = - 8
                                        x2 = - 8/15
                                                            S = {- 8/15, 0}
                                           
C)
           NO ES FACTORIZABLÇE
           HAY QUE USAR FÓRMULA RESOLUTIVA

                       x = (- b +/- √Δ)/2a
        
                                               Δ = b^2 - 4.a.c
                                                   = (- 12)^2 - 4(1)(- 69)
                                               Δ = 420
                      x = (12 +/- √420)/2
                         = (12 +/- 2√105)/2
                         = 6 +/- √105
                                               x1 = 6 - √105
                                               x2 = 6 + √105
                                                                       S = {6 - √105, 6 + √105}