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

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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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16 years ago
#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.........
0
16 years ago
#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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16 years ago
#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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16 years ago
#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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#26
(Original post by 4Ed)
yeah, not including the 4 other threads he's posted on this (in various subforums)

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#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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16 years ago
#28
Thank-you soooooooooo much, I actually understand now!
You're welcome. :-)
0
16 years ago
#29
(Original post by bono)
involving squares?

thats AS Level Pure 1.........
Doesn't mean it's harder though 0
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