So these are our two equations: [tex] 2x+y=12\\x=y-3 [/tex]
Before we can use elimination, subtract y on both sides of the first equation: [tex] 2x=-y+12\\x=y-3 [/tex]
Now we are able to use elimination. To eliminate the y variable, add the two equations together to get [tex] 3x=9 [/tex] . From here we can solve for x.
For this, just divide both sides by 3 and your first answer will be [tex] x=3 [/tex]
Now that we have the value of x, substitute it into either equation to solve for y:
[tex] 2*3+y=12\\6+y=12\\y=6\\\\3=y-3\\6=y [/tex]
In short, x = 3 and y = 6.
