Question

which one of the following quadratic
equations have two different real roots
A)x² + 4x + 5=0 B) x² - 6x +9=0
c) 2x² - 3x-9=0 D) 2x^+6x+5=0
​

Answer 1

Answer:

hey frnd here is your answer

Equation-

1. Don't have real roots bcoz Discriminat is less than Zero.
2. It is a perfect square so it have two roots but both are equal I. e both roots are 3.
3. Yes this equation have two different roots and roots are x=3 and x= -3/2.
4. This equation don't have real roots bcoz it's Discriminat is less than Zero.

so according to me C is the only correct option.

i hope u get your answer (see the attachment )

thnx for asking

plzz mark as brainlist..

Answer 2

Answer:

Since we are asked for real roots, only C has real different roots.

Step-by-step explanation:

For an quadratic equation to have different roots : Discriminant shouldn't be 0.

It means : b^2 - 4ac shouldn't be 0.

  For A :

         ⇒ ( 4 )^2 - 4( 5 )

         ⇒ 16 - 20

         ⇒ - 4

This is an imaginary condition. Roots will be different.

  For B :

         ⇒ ( 6 )^2 - 4( 9 )

         ⇒ 36 - 36

         ⇒ 0

Since result is not roots are not different.

  For C:

        ⇒ ( - 3 )^2 - 4( 2 )( - 9 )

        ⇒ 9 + 72

        ⇒ 81

Roots are different.

    For D ;

       ⇒ ( 6 )^2 - 4( 5 )( 2 )

       ⇒ 36 - 40

       ⇒- 4

This is imaginary condition, roots will be different.