Question

What is the solution set of x 2 + 5x - 5 = 0?

Answer 1

use the quadratic formula:

- B ± √ B2-4AC
x = ————————
2A

In our case, A = 1
B = 5
C = -5

Accordingly, B2 - 4AC =
25 - (-20) =
45

Applying the quadratic formula :

-5 ± √ 45
x = —————
2

Can √ 45 be simplified ?

Yes! The prime factorization of 45 is
3•3•5
To be able to remove something from under the radical, there have to be 2 instances of it (because we are taking a square i.e. second root).

√ 45 = √ 3•3•5 =
± 3 • √ 5

√ 5 , rounded to 4 decimal digits, is 2.2361
So now we are looking at:
x = ( -5 ± 3 • 2.236 ) / 2

Two real solutions:

x =(-5+√45)/2=(-5+3√ 5 )/2= 0.854

or:

x =(-5-√45)/2=(-5-3√ 5 )/2= -5.854

Answer 2

dont have any of those as answers

Answer 3

what answers u have?