one solution of x2-5x-1=0 is

Question

one solution of x²-5x-1=0 is

Answer 1

Use the quadratic formula to find x.

 

x = [1/(2a)] [-b ± √(b² - 4ac)]

 

a = 1

b = -5

c = -1

 

Plug these in, evaluate and simplify, and you will get both solutions.  Then pick either, since the problem asks for only one.

Answer 2

Using the quadratic formula with A = 1 B=-5 and C = -1

 

 

 X = [ -(-5) +or- square-root( (-5)^2 - 4*1*(-1))]/(2*1)

 

 

        [5 +or- square-root( 25 + 4) ]/2

 

        [ 5 +or- square-root(29)]/2

 

5.192582.... or -0.192582...

 

 

        

Answer 3

Hint:

 

Use the quadratic formula.