Kerjakan menggunakan rumus abc :

Jawab:

1. x² – 7x + 12 =0

  a=1   b= – 7  c= 12

  x = (-b±√(b²-4ac))/2a

     = ( 7±√(49 – 48))/2

     = ( 7 ± 1 )/2

x1   = (7 + 1)/2 = 4

x2  = (7 – 1)/2 = 3

2. 2x² + x – 6 =0

   a = 2   b = 1 c = -6

   x = (-b±√(b²-4ac))/2a

   x = ( -1±√(1 + 48))/4

   x = ( -1 ± 7 )/4

x1 = ( -1 + 7 )/4 = 3/2

x2 = ( -1 – 7 )/4 = -2