Question

Rhett is solving the quadratic equation zero equals X2 minus 2X -3 using the quadratic formula which shows the correct substitution of the value of a a,b and c into the quadratic formula

Answer 1

X^2-2x -3 =0
a =1 b =-2 and c = -3 

x = - (-2) +/- sqrt (-2)^2 - 4(1)(-3)
      --------------------------------------
                   2(1)

 x = + 2 +/- sqrt [(4) - 4(-3)]
       -------------------------------
                    2

 x = +2 +/- sqrt [4 + 12]
       --------------------------
                   2
x = +2 +/- sqrt[16]
      -------------------
              2

x = +2 +/- (4)
      -------------
             2

x = 2 + 4    or 2 -4 
      -------        ------
         2               2

x = 6/2      or   -2/2

x = 3   or x = -1