I need some help desperately with my maths!!! Watch

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Darkness
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#21
Report 16 years ago
#21
Let me try.

First, label your two equations as follows

(1) x^2+4(y^2)=24
(2)x+2y=6

From (2) you can rearrange to find x in terms of y i.e. x = 6-2y

Substitute this as your x in (1)...

(6-2y)^2+4(y^2)=24
(6-2y)(6-2y)+4(y^2)=24
36-24y+4(y^2)-4(y^2)=24
-24y=-12
24y=12
y=12/24
y=1/2
y=0.5

Now put this value of y into x=6-2y to find x...
x=6-2*0.5
x=6-1
x=5

Thus, y=0.5 and x=5
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username9816
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#22
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#22
(Original post by 4Ed)
his involved squares! although they did cancel out in the end..... there was probably a way to do it without the squaring, dunno.....
involving squares?

thats AS Level Pure 1.........
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GH
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#23
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#23
And people don't say we don't help people out. There must have been 5 complete workthroughs of this questions.
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4Ed
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#24
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#24
(Original post by bono)
involving squares?

thats AS Level Pure 1.........
well it turns out not to be in the end, since they DO actually cancel out to leave you with a linear equation.
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4Ed
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#25
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#25
(Original post by 2776)
And people don't say we don't help people out. There must have been 5 complete workthroughs of this questions.
yeah, not including the 4 other threads he's posted on this (in various subforums)
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CHAD
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#26
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#26
(Original post by 4Ed)
yeah, not including the 4 other threads he's posted on this (in various subforums)

sorry about that
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CHAD
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#27
Report Thread starter 16 years ago
#27
(Original post by Darkness)
Let me try.

First, label your two equations as follows

(1) x^2+4(y^2)=24
(2)x+2y=6

From (2) you can rearrange to find x in terms of y i.e. x = 6-2y

Substitute this as your x in (1)...

(6-2y)^2+4(y^2)=24
(6-2y)(6-2y)+4(y^2)=24
36-24y+4(y^2)-4(y^2)=24
-24y=-12
24y=12
y=12/24
y=1/2
y=0.5


Now put this value of y into x=6-2y to find x...
x=6-2*0.5
x=6-1
x=5

Thus, y=0.5 and x=5



Thank-you soooooooooo much, I actually understand now!
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Darkness
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#28
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#28
(Original post by CHAD)
Thank-you soooooooooo much, I actually understand now!
You're welcome. :-)
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Juwel
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#29
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#29
(Original post by bono)
involving squares?

thats AS Level Pure 1.........
Doesn't mean it's harder though
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