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Maths help

“Given that the solutions of the equation 3x^2-12x-11=0 can be written as c +/- root d, where c and d are rational numbers. Find the value of c and d.”
So far I’ve found the completed square which is 3(x-2)^2-23 and I’ve found c to be 2

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Reply 1
quadratic formula
Put your completed square form equal to 0. Now you have an equation with a single x you can solve for.
Reply 3
Original post by Luwei
quadratic formula

I’ve already tried and gotten 1/root 3 and it says it’s wrong
Reply 4
Original post by Dancer2001
Put your completed square form equal to 0. Now you have an equation with a single x you can solve for.


I’ve already tried and gotten root 69 over 3 and it says it’s wrong
Reply 5
Original post by zedndead
I’ve already tried and gotten root 69 over 3 and it says it’s wrong

Maybe show your working?
Reply 6
Original post by mqb2766
Maybe show your working?

No it’s one answer box image.jpg
Reply 7
Original post by zedndead
No it’s one answer box image.jpg

Please read the sticky at the top of the forum about getting hints.
The flipside is you're expected to show how you tried to get the solution.
Reply 8
Original post by mqb2766
Please read the sticky at the top of the forum about getting hints.
The flipside is you're expected to show how you tried to get the solution.

image.jpgThis is what I did and it says it’s wrong but I don’t get how
Reply 9
Original post by zedndead
image.jpgThis is what I did and it says it’s wrong but I don’t get how

You have sqrt(23/3)
What do you do then? What is d?
Original post by zedndead
“Given that the solutions of the equation 3x^2-12x-11=0 can be written as c +/- root d, where c and d are rational numbers. Find the value of c and d.”
So far I’ve found the completed square which is 3(x-2)^2-23 and I’ve found c to be 2


quadratic formula song
Reply 11
Original post by mqb2766
You have sqrt(23/3)
What do you do then? What is d?


I did square root it and I got the square root of 69 over 3, and it says it’s incorrect
Reply 12
Original post by Gundabad(good)
quadratic formula song

Already tried that
Original post by zedndead
Already tried that

https://www.youtube.com/watch?v=E2eVZFy9yzk

A German will help you remember.
Original post by zedndead
I did square root it and I got the square root of 69 over 3, and it says it’s incorrect

sqrt69)/3 is numerically the right amswer for c +/- d, but it asks for c +/- sqrt(d).
You already have the answer, d = ...
Reply 15
So I sqrt the sqrt of 69/3I just did that and I got 1.663993576, it asks for the answer to be in a fraction and it it’s simplest from
Original post by zedndead
So I sqrt the sqrt of 69/3I just did that and I got 1.663993576, it asks for the answer to be in a fraction and it it’s simplest from

What is the fraction INSIDE the square root.
Original post by mqb2766
What is the fraction INSIDE the square root.

download (3).jpg
Reply 18
Original post by mqb2766
What is the fraction INSIDE the square root.


Sqrt69/3
Original post by zedndead
Sqrt69/3

Last go, you have
2 +/- sqrt(*)
What is the fraction *?

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