use quadratic formula to solve

Question

^{x^2-3x-5=0}

Answer 1

marlene has an error...she miscalculated the discriminant, using the wrong c value.

Answer 2

Jennifer

 

 

x^2-3x-5=0

 

The quadratic formula is

 

-b ± √(b²-4ac)

-----------------

       2a

 

a = 1; b = -3; c = -5

 

-(-3) ± √[(-3)²-4(1)(-3)]

----------------------------

        2(1)

 

3 ± √(9+12)

--------------

     2

 

3 ± √21

---------

    2

 

3 + √21       3 - √21

---------    ,  ---------

    2                  2