posted by Chels .
Use the value of the discriminant to determine the number and type of roots for the equation: (x^2+20=12x-16)
1 real, irrational
2 real, rational
1 real, rational
For quadratics, either both roots are real or both are complex. In a special case where the discriminant is zero, there is one root.
In your case, the equation should be written in the ax^2 + bx + c = 0 form, which would be
x^2 -12x + 36 = 0.
discriminant = b^2 - 4ac = 144-144 = 0
So there is only one root.
x = -b/2a = 6, which is a rational number