Question

Solve x2 + 2x + 9 = 0.

Answer 1

@pooja195

Answer 2

Is this x^2 + 2x + 9 = 0?

Answer 3

Yes.

Answer 4

hope you are allowed complex solutions yes?

Answer 5

because the two answers will not be real numbers

Answer 6

Suppose so. These are my choices. http://prntscr.com/9262wo

Answer 7

oh ok
since 2 is even, easiest to complete the square

Answer 8

subtract 9 from both sides
what do you get?

Answer 9

4.5

Answer 10

Sorry I'm a little disoriented.

Answer 11

\[x^2+2x+9=0\] subract \(9\) from both sides

Answer 12

x^2 + 2x = -9

Answer 13

ok good

Answer 14

now what is half of 2?

Answer 15

1

Answer 16

right and \(1^2=1\) so go right to \[(x+1)^2=-9+1\\
(x+1)^2=-8\]

Answer 17

that means \[x+1=\pm\sqrt8\\
z=-1\pm\sqrt{-8}\]

Answer 18

Is there more to do?

Answer 19

write \(\sqrt{-8}\) as \(\sqrt{8}i\)

Answer 20

subtract 1 from both sides?

Answer 21

then since \(\sqrt8=2\sqrt2\) final answer is \[-1\pm2\sqrt2 i\]

Answer 22

Oh!

Answer 23

Wouldn't it be -1 +2i sqrt 2?

Answer 24

http://prntscr.com/9264c1 The answer choices put the i after the 2.

Answer 25

yeah what you said

Answer 26

Alright, thanks.