Answer :
so use subsituteion
make y-x=-9
change it to subsitute
y-x=-9
add x to both sides
y=x-9
susitute x-9 for y in y+2x=3
x-9+2x=3
3x-9=3
add 9 both sides
3x=12
divide both sides by 3
x=4
subsitute
y=x-9
y=4-9
y=-5
x=4
y=-5
(4,-5)
make y-x=-9
change it to subsitute
y-x=-9
add x to both sides
y=x-9
susitute x-9 for y in y+2x=3
x-9+2x=3
3x-9=3
add 9 both sides
3x=12
divide both sides by 3
x=4
subsitute
y=x-9
y=4-9
y=-5
x=4
y=-5
(4,-5)
