1. Answer :B. 2 rational roots
Discriminant D >0 -----> 2 rational roots
Discriminant D =0 -----> 1 real root
Discriminant D <0 -----> 2 imaginary roots
D = 28 >0 So 2 rational roots
2. Answer : 2 complex roots
5x^2 -2x+1=0
Discriminant D =
D = -16 <0 so 2 complex roots
3. 3x^2 +9=5-4x

Now solve for x, use quadratic formula



x =

The roots are complex
Solution set is 
4. x^2-6x-5=0


Solution set 