Question 654529
2x  +  y  =1
 x  -  y  =11
_____________
3x  +  0  =12
so x=4. Then substitute 4 for x back in one of te original equations:
2(4)+ y = 1
8+y=1
y= -7
Now stick this value for y back in the second equation,just to dbl check!
4-(-7)=11!!
=)That's it!