Question

if 1 is a root of the quadratic equation 3x​2+ax-2=0 and the quadratic equation a(x2+6x)-b=0 has equal roots,find the value of b.

Answer 1

Answer:

b=9

Step-by-step explanation:

given x=1

given  3x^2 + ax - 2 =0

           3(1) + a -2 =0

            a=  -1

      now ax^2 +6ax -b

              -x^2 -6x -b=0   given a= -1

                x^2 + 6x + b =0

       it has equal roots d=0

                  0=b^2 -4ac

                   0 = 36 - 4b

                   4b = 36

                    b =9