Question

Hey! Describe the roots of the equation shown below:

3x^2-10x-5

Answer 1

Hey! is for horses, saying "please" may get you help.

Answer 2

Do you know the FOIL method of multiplying binomials?

Answer 3

First of all that is an "expression" and it is not an "equation." Can you tell me why?

Answer 4

But obviously it isn't.

Answer 5

Correct. An equation MUST have an equals sign.

Answer 6

So what is it suppose to equal???

Answer 7

God I'm so dumb. Sorry. It's supposed to equal 0. I didn't see that I missed that while typing

Answer 8

np, so $$3x^2-10x-5=0$$

Answer 9

Correct!

Answer 10

Ok, what are the factors of 3?

Answer 11

I'm not sure... Would it be the other numbers in the equation?

Answer 12

what two numbers multiplied together give 3?

Answer 13

For a quadratic equation\[ax^2+bx+c=0\]
the roots can be found using the quadratic formula
\[x_{1,2}=\frac{-b\pm\sqrt{b^2-4ac}}{2a}\]

Answer 14

Still not sure. 3*1?

Answer 15

Yes.

Answer 16

Phew thought it was a trick question

Answer 17

and how about 5?

Answer 18

3*1.66?

Answer 19

what two numbers multiply together to give 5?

Answer 20

OH. 5*1.

Answer 21

put those factors into $$3x^2-10x-5=(ax+b)(cx+d)$$ and usee FOIL until you get the right answer

Answer 22

Could you put those factors into $$3x^2-10x-5=(ax+b)(cx+d)$$ so I can see where they are placed?

Answer 23

the solution is not integer
u can describe the roots like this
there exist c belong to (0,-1) { u might find onother interval }
such that 3c^2-10c-5

Answer 24

@mathhelpplease12 @ikram002p is right

Answer 25

Oh okay. Thank you guys so much for the help!

Answer 26

thanks for asking

Answer 27

http://www.wolframalpha.com/input/?i=3x^2-10x-5%3D0
This is to check your answer.
You can practice factoring polynomial at
http://www.saab.org/mathdrills/factor.cgi

Answer 28

wow... I thought this question would require the use of the discriminant...

\[\Delta = b^2 - 4ac\]

as the question says..."Describe the roots....

would have saved a lot of work...

but hey... reading the question is the biggest part of answering a question