Y=x^2-6x-8 Find roots by factoring or quadratic formula if factoring doesnt work.

Question

Y=x^2-6x-8    Find roots by factoring or quadratic formula if factoring doesnt work.

anonymous · Answer

You sure it's -8?

anonymous · Answer

yup, y=x^2-6x-8.    Yup. Positive

anonymous · Answer

You're gonna want to use the quadratic formula for this one.

anonymous · Answer

Thought so. I dunno why, but the first time i tried, i got -38,0 and like -26,0 or something like that. i knew it was completely wrong tho...Haha

anonymous · Answer

Cause the only integer factors of 8 are 4 and 2, but they can't both be negative (to give -6) without the 8 being positive.

anonymous · Answer

Hmm..

anonymous · Answer

So you're gonna get non-integers

anonymous · Answer

So Decimals... Hopefully theyre only .5

anonymous · Answer

polpack will you help me?

anonymous · Answer

K i'll solve it.

anonymous · Answer

I just leave em as fractions usually

anonymous · Answer

but then my teachers rarely let us use calculators

anonymous · Answer

She's fine with us using them. she just likes us to try without them. you can play cards on our calculators..haha

anonymous · Answer

polpak. can you help me

anonymous · Answer

$$x=\frac{6 \pm\sqrt{36 - 4(-8)}}{2} = 3 \pm \frac{\sqrt{68}}{2} = 3 \pm \frac{\sqrt{4\times 17}}{2} = 3 \pm \sqrt{17}$$

anonymous · Answer

but theres no variables in that. :(

anonymous · Answer

those are the roots, sorry.

anonymous · Answer

to factor just say $y = (x-3+\sqrt{17})(x-3-\sqrt{17})$

anonymous · Answer

polpak i need help please!

anonymous · Answer

ohh, so all i need to do is...ohh, okay...THANKS!

anonymous · Answer

ohh, so all i need to do is...ohh, okay...THANKS!