# Maths question

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#1
express 3x^2-18x+16 in the form a(x-b)^2+c

no idea!
0
1 month ago
#2
(Original post by lala5646)
express 3x^2-18x+16 in the form a(x-b)^2+c

no idea!
Completed square form - are you studying GCSE?

If you haven't learned this then expand out the brackets and compare coefficients - post your working
0
#3
(Original post by Muttley79)
Completed square form - are you studying GCSE?

If you haven't learned this then expand out the brackets and compare coefficients - post your working
so would it be 3(x^2-18x)+16
0
1 month ago
#4
(Original post by lala5646)
so would it be 3(x^2-18x)+16
No - that's not the same -- if you are going to do it like this you need to take out a factor of 3 from 18 too

a(x-b)^2+c = what when expanded?
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#5
(Original post by Muttley79)
No - that's not the same -- if you are going to do it like this you need to take out a factor of 3 from 18 too

a(x-b)^2+c = what when expanded?
ah so would it be 3x(x - 6)+16
0
1 month ago
#6
Start by just taking out the 3 from x^2-18x
So it is 3(x^2-6x)+16
Then complete the square
Last edited by MayaVellichor; 1 month ago
0
#7
how do u do that pls
0
1 month ago
#8
(Original post by lala5646)
ah so would it be 3x(x - 6)+16
Just take out the factor of 3 - you need the other terms
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#9
i dont get it
0
1 month ago
#10

This should explain the method
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#11
so would it be 3(x^2 - 2x) + 9
0
1 month ago
#12
Here's my solution.
0
1 month ago
#13
(Original post by lala5646)
so would it be 3(x^2 - 2x) + 9
Not quite,
0
1 month ago
#14
0
#15
love u all
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