Solve for the system of linear equations x+y=4 2x+3y=0

X+y=4

2x+3y=0

x=4-y

2 (4-y) + 3y=0

8-2y+3y=0

8+y=0

y=-8

x + (-8) = 4

x-8=4

x=12

Solve x+y=4 for x

x+y+-y=4+-y (add - y to both sides)

x=-y+4

substitute - y+4 for x in 2x+3y=0

2x+3y=0

2 (-y+4) + 3y=0

y+8=0 (simplify both sides of the equation)

y+8+-8=0+-8 (add - 8 to both sides)

y=-8

substitute - 8 for y in x=-y+4:

x=-y+4

x = - (-8) + 4

x=12 (simplify both sides of the equation)

answer is x=12 and y=-8