Question

find the solution set of x^2+3x+9=0

Answer 1

use quadratic formula

Answer 2

can you help me i missed a bunch of school and that is what we learned when i missed

Answer 3

Surely :)
If you have a quadratic equation of the form
\[\large \color{red}ax^2 +\color{blue}bx+\color{green}c=0\]

Then the solutions would be given by this formula~
\[\Large x=\frac{-\color{blue}b\pm\sqrt{\color{blue}b^2-4\color{red}a\color{green}c}}{2\color{red}a}\]

Answer 4

Just identify correctly your values for a,b, and c, and plug them in :)

Answer 5

ok... :/ is a 3 b 9 and c0

Answer 6

No... look again~
a is the coefficient (number beside) \(x^2\)
b is the coefficient of \(x\)
c is the number with no x attached to it.

Answer 7

a=1 b=3 and c=9

Answer 8

Good :)
Now just plug them into this formula. It would give you the two solutions you need :)
\[\Large x=\frac{-\color{blue}b\pm\sqrt{\color{blue}b^2-4\color{red}a\color{green}c}}{2\color{red}a}\]

Answer 9

\[-3\pm \sqrt{3^2-4(1)(9)}\]

Answer 10

for the top row

Answer 11

Very nice :)
For the bottom "row" it's just 2(1) = 2, aye? ^.^

Answer 12

not really but i got -27/2

Answer 13

Okay... let's keep things real... why don't you simplify the inside of that radical first?

Answer 14

is the answer -3+3isquareroot3/2, -3-3isquareroot3/2

Answer 15

Yeah, that's it.
I don't know how you got that, but who can deny its correctness? :P
\[\Large x = \frac{-3\pm\sqrt{3^2-4(1)(9)}}{2(1)}=\frac{-3\pm \sqrt{-27}}{2}\]
\[\Large x = \frac{-3\pm\sqrt{-1\cdot9\cdot3}}{2}=\frac{-3\pm3\color{red}i\sqrt{3}}{2}\]

Answer 16

oh thank heavens hahaha