Answer :
x+y=4
2x+y=6
make first equation negative
-x-y=-4
add to first equation
2x-x+y-y=6-4
x=2
subsitute
x+y=4
2+y=4
y=2
or
x+y=4
subtract x from both sdies
y=4-x
subsitute 4-x for y in second equation
2x+4-x=6
x+4=6
x=2
2x+y=6
make first equation negative
-x-y=-4
add to first equation
2x-x+y-y=6-4
x=2
subsitute
x+y=4
2+y=4
y=2
or
x+y=4
subtract x from both sdies
y=4-x
subsitute 4-x for y in second equation
2x+4-x=6
x+4=6
x=2
