Rationalize the denominator of https://api.agilixbuzz.com/Resz/~Ey6YBAAAAAA81ZXByil0iA.RBcymAkaS7gygkcdGLtgrA/19809088,B87/Assets/assessmentimages/alg%202%20pt%202%20u3l8%2011.jpg @wolf1728 @thesmartone
@zzr0ck3r
@whpalmer4
multiply top and bottom by \(2+\sqrt{6}\)
is it 2-
@zzr0ck3r
i thought you multiply the denominator
\[4-\sqrt{6}\] i got this for numerator but don't know what to do now @TheSmartOne
@agent0smith
@Zarkon
@pooja195
@Kainui
Describe to me what you did, and where your answer is so far.
i multiplied the denominator and numerator
@mjdennis
@Jaynator495
@rebeccaxhawaii
@zepdrix
@TheSmartOne
I don't understand "multiplied the denominator and numerator" Did you multiply them together? Did you multiply them both by one thing?
OK, let's start over. Simplify 2 + √6 ------ 2 - √6 Right?
\[\frac{ 2+\sqrt{6} }{ 2-\sqrt{6} } \times \frac{ 2-\sqrt{6} }{ 2-\sqrt{6} }\]
OK, that was close. You really need to use 2 + √6. I think you will see why that is better when you do it
Sorry, I mean 2 + √6 on both top AND bottom. One sec, I will put it in the equation editor.
\[\frac{ 2+\sqrt{6} }{2-\sqrt{6} } \times \frac{ 2+\sqrt{6} }{2+\sqrt{6} }\]
ok so what do i do now?
@mjdennis
This is the same as: \[\frac{ (2+\sqrt{6}) \times (2+\sqrt{6}) }{ (2-\sqrt{6}) \times (2+\sqrt{6}) }\]
So do those two multiplications out
\[\frac{ 4+\sqrt{36} }{ 4-\sqrt{36} }\]
is that right?
The denominator is right. The numerator is the form (a+b)(a+b) = a^2+2ab+b^2, so try the numerator again,please.
im not really sure what that means?
it means when you multiply (2+√6)×(2+√6), you have to add _four_ terms: (2×2) (2×√6) (√6 × 2) (√6 × √6) and add those up.
4 2sqrt6 2sqrt6 6
is that right?
Yes, but add them up. You may want to practice multiplying mixed numbers (like 2+√6) some more.
Youw ill need that skill more in math.
Ha, sorry, "You will.."
@18jonea , I'll hang out a bit in case you come back.
im back sorry had to get a snack
NP. Gotta stay fueled up.
4.89897948557 i got this for 2 square root 6
Not sure how you are supposed to put the answer. Does the problem say?
I would have left the √6 alone in my answer.
o ok
Let's follow that through, just in case, then you also have that answer.
-5 -1 \[-5-2\sqrt{6}\] \[-\frac{ 5 }{ 2}-\sqrt{6}\]
are my options
4+6 is 10, but I figure you got that part. 2√6 +2√6 is 4√6, right? So the top is 10+√6
yes
The bottom was 4-√36 . Can you reduce that?
\[\sqrt{6}\]
sorry just 6
Did you mean 4-6? That reduces further still.
-2
Oops. Top should have been 10+4√6 I'll re do it
d?
Put them back together and we are almost done: \[\frac{ 10+4\sqrt{6} }{ -2 }\] and you can use distribution to split the -2 over both halves: \[\frac{ 10 }{ -2 } + \frac{ 4\sqrt{6} }{ -2 }\] Can you bring it home? Only one match among your choices.
Not d
c
I guess. You didn't label the choices!
\[-5-2\sqrt{6}\]
@mjdennis
Wait, I helped you through all the tough stuff, and you would like me to believe that you cannot divide 10 by -2, or divide 4√6 by -2 , and be confident in the answer?
-5 is the 10
So, I think you got it from here.
just dont know the square root
im 99% sure it is c
OK. Right, 10/(-2) is -5. Only one answer had -5, so be confident in that. When we write √6, we are using "√6" as a symbol. It stands in for an number a little bigger than 2.449 and a little smaller than 2.450. So we can just treat it as any other number, but leave it as a symbol. Suppose I asked you to find 20/-2 ? You could say "20 is 2*10, and I know 10/-2 is -5, so 20/-2 is twice -5, so 20/-2 is -10. Same for 4√6/-2. It is =2√6. We never have to touch the √6, because it is the simplest form.
Good luck! Gotta go.
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