Question

Help a girl out pls

What are the exact solutions of x2 - X-4 = 0, where -b + √b² - 4ac X= 2a Ox= -115 2 Ox= 11 15 2 O x = 1:17 2 0x==137​

Answer 1

1 ± sqrt(17)

x = ---------------------------

2

Explanation:

x^2 - x - 4 =0

Using the quadratic equation

-b ± sqrt(b^2 -4ac)

x = ---------------------------

2a

Where ax^2 +bx +c

We know a =1 b = -1 c = -4

-(-1) ± sqrt((-1)^2 -4(1)(-4))

x = ---------------------------

2(1)

1 ± sqrt(1 +16)

x = ---------------------------

2

1 ± sqrt(17)

x = ---------------------------

2