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#1 2005-10-06 08:00:06
- the stuck guy
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help plz
i have a question infront of be that reads" write down the gradient and y-intercept for each of these straight lines" then it says "b) 2y = 4x - 12 " i know how to set up the table but why is there a 2y what do i do when i am trying to find the co-ordinates like x|0|1|2|3|4|5|
y|?
#2 2005-10-06 10:09:56
- MathsIsFun
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- Registered: 2005-01-21
- Posts: 7,713
Re: help plz
Straight lines are usually written in the form:
y = mx + b
(see Equation of a Straight Line)
So, you can change your equation to suit:
Start with: 2y = 4x - 12
Divide by 2: y = 2x - 6
Then for any x you can calculate y, for example: if x=4, then y = 2 × 4 - 6 = 8-6 = 2
And you can see that the gradient is 2 (because y changes by 2 when x changes by 1)
And the y intercept is when x=0, so: y=2x-6= 2 × 0 - 6 = -6
"The physicists defer only to mathematicians, and the mathematicians defer only to God ..." - Leon M. Lederman
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#3 2005-10-06 16:13:35
- Jai Ganesh
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- Registered: 2005-06-28
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Re: help plz
In India,
y = mx + c
where c is the y intercept and -x/y is the slope (or gradient),
when written as y - mx - c = 0 
It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.
Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.
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#4 2005-10-06 18:01:08
- MathsIsFun
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- Registered: 2005-01-21
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Re: help plz
Probably the British tradition?
"The physicists defer only to mathematicians, and the mathematicians defer only to God ..." - Leon M. Lederman
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#5 2005-10-06 20:39:22
- Jai Ganesh
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- Registered: 2005-06-28
- Posts: 50,415
Re: help plz
Yes, very much British
It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.
Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.
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