# linear equations by addition method

• Oct 15th 2012, 05:34 PM
Mjf
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
• Oct 15th 2012, 05:47 PM
MarkFL
Re: linear equations by addition method
Multiply the first equation by -15, then add it to the second equation to eliminate y.
• Oct 15th 2012, 05:51 PM
Mjf
Re: linear equations by addition method
thanks alot
• Oct 15th 2012, 05:56 PM
Mjf
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
• Oct 15th 2012, 06:11 PM
MarkFL
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\$