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Help!!

by sana.noor » Fri Jan 25, 2013 9:16 am
If r and s are the two roots of the equation x^2 + 8x +15 = 0, and r<s, what is the value of s-r?
a)-8
b) -2
c) 2
d) 7
e) 8
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by ceilidh.erickson » Fri Jan 25, 2013 9:55 am
This is incorrectly labeled "Sentence Correction." Relabel it, and I'll be happy to post a reply.
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by hemant_rajput » Fri Jan 25, 2013 9:56 am
we know sum of roots = (-b/a) and product of roots = c/a

so here now a =1, b = 8 and c =15
s+r = -8/1
s*r = 15/1

(s-r)^2 = (s + r)^2 - 4(s*r) ==> (-8)^2 -(4*15) ==> 64 -60==>4

s-r = 2

option c
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by hemant_rajput » Fri Jan 25, 2013 9:58 am
hey sana.noor, can you tell me how do you have a tag line in every post. I'm referring to this "If you found my Post really helpful, then don't forget to click the Thank/follow me button. Smile"
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by ceilidh.erickson » Fri Jan 25, 2013 10:00 am
hemant_rajput wrote:hey sana.noor, can you tell me how do you have a tag line in every post. I'm referring to this "If you found my Post really helpful, then don't forget to click the Thank/follow me button. Smile"
Go to "My profile" then click "Account Settings." Scroll down to "Signature," and you can create a signature that will be added to all of your posts.
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