Solve for both systems x - 5y = 40 and 3x + y = - 40

x - 5y = 40

x - 5y+5y = 40+5y

x= 40+5y

3x + y = - 40

3(40+5y) + y = - 40

3(40) (3)(+5y) + y = - 40

120+15y+y=-40

120+16y=-40

120+16y-120=-40-120

16y=-160

16y/16=-160/16

y=-10

x= 40+5y

x= 40+5(-10)

x= 40-50=-10