Question

What are the solutions for the quadratic
equation x2(to the second power) + 6 x = 16 ?

Answer 1

easy

Answer 2

Factorise. Found the solutions in 5 seconds! :) (Solutions are 8 and -2).

Answer 3

(x+8)(x-2) x=-8 or 2

Answer 4

you're wrong tommo

Answer 5

gf your 5 secs

Answer 6

how did you get 8 and 2

Answer 7

Onc you have the factors of your quadratic, in this case x+8 and x-2, we set each one equal to zero and solve for x. What you are trying to do is find out when your quadratic function is equal to zero. This can happen in two ways, either x+8=0 or x-2=0. Solving each for x, we know our quadratic is equal to zero when x=2 or x=-8

Answer 8

@Tai, I'm good at Maths, OK! I am doing a degree, so have to be! :) So I'm not wrong and you were kidding when you said I was, weren't you?

Answer 9

what did you factor to get -8 and 2 ? if you factored 16 wouldnt it be 4 and 4 ???

Answer 10

@tommo_lcfc x is 2 or -8...if you're doing a degree you've gotta reconsider re-taking highschool lol

Answer 11

or maybe you're just tired?

Answer 12

factorises to (x+8)(x-2) --> so you tell me what the values of x are lol.

Answer 13

@ashleysmith 4 and 4 would not work as they cannot add up to 6!!! :)

Answer 14

@tommo, yes, you are incorrect

Answer 15

Hey don't judge him, everyone makes mistakes, there's nothing to be ashamed of, we're not robots ! ;)

Answer 16

thanks guys !

Answer 17

guys look...\[x^2+6x-16=0\]
\[x^2+8x-2x-16=0\]
\[x(x+8)-2(x+8)=0\]
\[(x-2)(x+8)=0\]
Hence: x=2 or x=-8

Answer 18

and maybe i was a bit harsh, soz

Answer 19

@ tommo_lcfc what kind of a degree are you taking?

Answer 20

Another way to get the factors is to try to find two numbers that multiply to give
-16 and add up to give +6. Some trial and error yields 8 and -2. Thus your factors are (x+8)(x-2)