I got some trouble with finding out how to calculate this..
Question: Where do these lines cross eachother x + 3y +3=0 and x - 3y +2 =0
First i tried to solve y and got this far
y = -1/3x - 1 = 1/3x+2/3 (divided all with 3)
but im not even sure if that is right. can anyone please explain how i can do this?
Last edited by schwebba (2005-07-25 12:32:03)
Solving the two equations, you get
x = -5/2, y = -1/6
Hence, the two lines cross at
How the two equations are solved:-
First equation can be written as x+3y = -3
The second equation can be written as x - 3y = -2
Adding the two, we get 2x = -5, or x = -5/2
Substituting this value in equation (1) -5/2 + 3y = -3
3y = -3 + 5/2
3y = -1/2
y = -1/6
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wow thanks i think i get it now. you sure cleared things up a bit
gonna practise some more on this..
thanks a lot for that nice solution
And for all those avid graphers out there, I have a little tool to figure out lines from points here: http://www.mathsisfun.com/straight-line … ulate.html