Question

What are the exact solutions of x2 - 3x - 1 = 0?

Answer 1

you need to factor this out into (x -a)(x-a)=0 with what i have there can you figure it out?

Answer 2

I have a real difficult time trying to figure these out.

Answer 3

ok well i am here to help then.

Answer 4

Thank you! Please do!

Answer 5

The LHS does not factor.\[x=\frac{1}{2} \left(3\pm \sqrt{13}\right) \]

Answer 6

Um, pretty sure you're not going to be able to factor that @PaulK...

Quadradic:
\[x=\frac{-b\pm \sqrt{b^2-4ac}}{2a}\]

Answer 7

a = 1
b = -3
c = -1

Answer 8

ax\(^2\) + bx + c = 0

Answer 9

well lots of learning done here by giving out of answers so quickly....

Answer 10

I didn't give out any answer. Only one answer was given out. ;-)

Answer 11

Thanks guys! I appreciate the help! :D

Answer 12

The reason you can't factor it is because there is nothing that can be multiplied together to give you -1 and added together to give you -3

Answer 13

F O I L in other words

Answer 14

One more question..... the end equations... is it positive 3 or negative 3?

Answer 15

@thenderson75 Look at the original equation and see if you can identify the coefficients a, b, & c ok?

Answer 16

I already got the equation and I've figured the whole thing but I wanted to make sure if it was positive or negative before I submit the answer.

Answer 17

There will be two answers because you have a second-order equation, aka. a quadratic equation. Even if it's the same answer twice, you'll always have two answers.

Answer 18

Type it in your calculator once with the addition and once with the subtraction and you'll see ;-)

Answer 19

It becomes some messy decimals

Answer 20

But if you must know, that's how

Answer 21

It stops at the equation and one of the choices is negative and one is positive.

Answer 22

In a lot of real world problems you'll be throwing away the nonsensical negative answer (i.e.: if "x" was "t", and "t" meant "time", you can't have negative time)

Answer 23

Thank you so much for your help!

Answer 24

1/2 (3+\(\sqrt{13}\)) = ?
1/2 (3-\(\sqrt{13})\) = ?

Answer 25

You can do this even on a basic calculator. If it's for a math class, put down both answer in non-decimal form. If it's for a physics or chemistry class or something, see if there's a root you can get rid of because it's nonsensical and put in decimal form with the correct sig figs and the correct units.

Answer 26

thx guys @agentx5