Question

Solve this quadratic equation using the quadratic formula. x^2 + 8x - 5 = 0

Answer 1

\[\frac{ -b \pm \sqrt{ b^2 - 4ac} }{ 2a }\]

Answer 2

use the quadratic formula. never fails.

Answer 3

okay I get that part

Answer 4

yeah so
a = 1
b = 8
c = -5

Answer 5

plug those numbers in for each variable.

Answer 6

\[\frac{ -8 \pm \sqrt{ 8^2 - 4(1)(-5)} }{ 2(1) }\]

Answer 7

can you do this simple algebra?

Answer 8

ya hang on

Answer 9

I got \[-8\pm \sqrt{84}\]

Answer 10

ya

Answer 11

ya

Answer 12

well there is going to be two different solutions, what did you get?

Answer 13

idk really im confused

Answer 14

\[x = \frac{ -8 + \sqrt{84} }{ 2 }\]

and

\[x = \frac{ -8 - \sqrt{84} }{ 2 }\]

Answer 15

Simplify the Radicals.

Answer 16

okay hang on

Answer 17

1.16515
-17.16515

Answer 18

yeah but its easier and better if you left it in terms of radicals.

Answer 19

what

Answer 20

\[\sqrt{84} = \sqrt{4 \times 3 \times 7} = \sqrt{2^2 \times 3 \times 7} =2 \sqrt{3 \times 7} = 2\sqrt{21}\]

Answer 21

okay so it will b \[x=2\sqrt{21}\]

Answer 22

no.

Answer 23

sad

Answer 24

\[x = \frac{ -8 + 2\sqrt{21} }{ 2 }\]

and

\[x = \frac{ -8 - 2\sqrt{21} }{ 2 }\]