so assuming x and y remain constant, we can make one of the place holders negative and add the equations together to cancel each other out so
we can cancel out the y terms since 5 is close to 10
(x+5y=6) times 2=2x+10y=12
add this to 6x-10y=12
2x+6x+10y-10y=12+12
8x=24
divide both sides by 8
x=3
subsitute into first equation
x+5y=6
3+5y=6
5y=3
y=3/5
x=3