linear equations by addition method

I'm usually pretty decent doing these problems, but one is stumping me for some reason. I'm drawing a blank on the following turning the fraction into a simple line formula to solve with. It goes like this.

x over 3 plus y over 3 equals 0 so x/3 + y/3 = 0 is the first one and the second is 10x + 5y = -1

Re: linear equations by addition method

Multiply the first equation by -15, then add it to the second equation to eliminate *y*.

Re: linear equations by addition method

Re: linear equations by addition method

What would you do with a problem like y=5/3x so y = 5 over 3 times x and your second would be x+y=2

Re: linear equations by addition method

I would multiply the first equation by 3 and arrange as:

$\displaystyle 5x-3y=0$

and multiply the second equation by 3 to get:

$\displaystyle 3x+3y=6$

then add to eliminate *y*.

Re: linear equations by addition method

awesome that makes sense thanks