Answer:
see below
Explanation:
x=y+3
Subtract 3 from each side
x-3 = y
y = x-3
y=-4x-3
We have both equations in slope intercept form
y = mx +b where m is the slope and b is the y intercept
graph is below
They both have the same y intercept so they intersect at (0,-3)
Substitution
x=y+3
y=-4x-3
Substitute the second equation into the first equation
x=y+3
x = -4x-3 +3
x = -4x
Add 4x to each side
5x =0
x=0
y = -4x-3
y = 0-3
y = -3
(0,-3)
Additon
x=y+3
Subtract y from each side
x-y = 3
y=-4x-3
Add 4x to each side
4x+y =-3
Add the equations together to eliminate y
x-y = 3
4x+y =-3
-----------------
5x +0y =0
5x = 0
x=0
Now solve for y
y = -4x-3
y = 0-3
y = -3
(0,-3)