y=mx+c

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I dnt understand this question- any help will be appreciated :P

a straight line passes through (0,-2) and (3,10) Find the equation of the straight line.

Plz could yue start from the basics cuz I still dnt properly understand the y=mx+c

Posted: 08-06-12 13:16 by в

m stands for the steepness of the line - the gradient and the +c is where the line crosses the y-axis when x is 0 (it just means and something, it's not always a +)

Since it passes through (0,-2) that means it crosses the y-axis at -2 so the intercept is -2

To find the gradient you need to find the difference between the two x and y coordinates, so the difference between 10 and -2 (for y) is 12 and the difference between 3 and 0 (for x) is 3.

The gradient is y/x so you do 12/3 which is 4.

That means your gradient is 4x.

So the equation is y = 4x -2

Hope it helps =) ( and I haven't made any mistakes :/ )

Posted: 08-06-12 15:23 by Joanne

ohhh i kinda get it fank yueee so much! -**-

Posted: 08-06-12 15:25 by в

m is the gradient (steepness)of the line and c is the y intercept (where the line cuts the y axis)

the m tells you how far up the line goes eg. y=2x+3 so the line will go across one and up 2 for every point

So for your question you need to draw a graph and put on the coordinates and draw a line through them so you can work out the equation

You work out c from where the line cuts the y axis (vertical line) and to work out the m pick a point and go across one square and see how many squares you go up or down to reach the line (if it goes down it is a negative number and if it goes up its a positive number)

Now put them into the equation y=mx+c and thats your answer

Hope this helps :)

Modified twice, last modified by Lollipop on Fri 8th June, 2012 @ 15:31

Posted: 08-06-12 15:29 by Lollipop

thnkx yuee :) it really does help !

Posted: 08-06-12 15:35 by в

Let me know if you need anymore help with anything :)

Posted: 08-06-12 15:43 by Lollipop

KK.. I probz will so far im gwd thanx Lollipop :)

Posted: 08-06-12 15:44 by в