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# Can someone help me with this question please??

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Expand the following into the general form y=ax^2+bx+c

y=-1/2(x+4)^2 2-6

The answer is said to be y=-1/2x^2-4x-14
How do they get this?
2. (Original post by DenizS)

Expand the following into the general form y=ax^2+bx+c

y=-1/2(x+2)^2 2-6

The answer is said to be y=-1/2^2-4x-14
How do they get this?
Expand and simplify to get it into the wanted form.
3. (Original post by RDKGames)
Expand and simplify to get it into the wanted form.
I still don't know how to get the answer though
4. (Original post by DenizS)
I still don't know how to get the answer though
You wrote out either the question wrong, or the answer. Also show your working, you need to have and an terms in there so you need to expand the brackets.
5. (Original post by RDKGames)
You wrote out either the question wrong, or the answer. Also show your working, you need to have and an terms in there so you need to expand the brackets.
I've written down the question and answer exactly how the worksheet has.
6. (Original post by DenizS)
I've written down the question and answer exactly how the worksheet has.
What's this then??? The 2-6?

(Original post by DenizS)
y=-1/2(x+2)^2 2-6
7. (Original post by DenizS)
I've written down the question and answer exactly how the worksheet has.
could you post a pic of the sheet ? *
8. (Original post by RDKGames)
What's this then??? The 2-6?
I was wondering the same??? otherwise i'd give it a shot hahaha
9. (Original post by beth-robinson99)
I was wondering the same??? otherwise i'd give it a shot hahaha
I want to say it's supposed to be +2(-6) which would fit the 14 constant after expansion of (x+2)2, but the coefficient of x would be wrong.
10. y=-1/2(x+4)^2 2-6

The answer is said to be y=-1/2x^2-4x-14

-0.5(x+4)^2 = -0.5(x^2+8x+16) =-0.5x^2 - 4x - 8

so whatever the 2-6 is must make the -8 to -14? is it just meant to be -6?
11. (Original post by DenizS)

Expand the following into the general form y=ax^2+bx+c

y=-1/2(x+4)^2 2-6

The answer is said to be y=-1/2x^2-4x-14
How do they get this?
Anyway, your actual question is which is equal to as required. Just expand the brackets and manipulate it from there. Do you know how to do that?
12. (Original post by RDKGames)
Anyway, your actual question is which is equal to as required. Just expand the brackets and manipulate it from there. Do you know how to do that?
You only need to put the expression into the form y= ax^2 + bx + c

I just don't know how you got from the first expression to -1/2x^2-4x-14
13. (Original post by DenizS)
You only need to put the expression into the form y= ax^2 + bx + c

I just don't know how you got from the first expression to -1/2x^2-4x-14
But that's what I'm saying you need to do, you need to expand the brackets first!
14. (Original post by DenizS)
You only need to put the expression into the form y= ax^2 + bx + c

I just don't know how you got from the first expression to -1/2x^2-4x-14

look at my comment above here somewhere, i showed you how to do it?
expand brackets out
half it
-6
15. (Original post by RDKGames)
But that's what I'm saying you need to do, you need to expand the brackets first!
-1/2(x^2 +8x+ 16) 2-6
16. (Original post by beth-robinson99)
y=-1/2(x+4)^2 2-6

The answer is said to be y=-1/2x^2-4x-14

-0.5(x+4)^2 = -0.5(x^2+8x+16) =-0.5x^2 - 4x - 8

so whatever the 2-6 is must make the -8 to -14? is it just meant to be -6?
I don't get why your answer is 6. I know how you worked it out, but that isn't the answer on the worksheet?
17. (Original post by DenizS)
-1/2(x^2 +8x+ 16) 2-6
Correct expansion but.... why did you keep the "2-6" when you clearly made a typo on it??????

It should just be -6 after the bracket. Now multiply everything in the bracket by -1/2 and simplify.
18. (Original post by RDKGames)
Correct expansion but.... why did you keep the "2-6" when you clearly made a typo on it??????

It should just be -6 after the bracket. Now multiply everything in the bracket by -1/2 and simplify.
I kept the "2-6" because that was what was typed on the worksheet
19. (Original post by DenizS)
I kept the "2-6" because that was what was typed on the worksheet
Silly worksheet, get rid off the 2 because it doesn't make sense. The question should read:
20. (Original post by RDKGames)
Silly worksheet, get rid off the 2 because it doesn't make sense. The question should read:
Thank you, I understand the answer now

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