Solve by substitution 2y=x+1 - 2x-y=7

-2x-y=7

Add 2x to both sides

-y = 2x+7

Multiply both sides by-1

Y = - 2x-7

2y=x+1

2 (-2x-7) = x+1

-4x - 14. = x+1

Add 14 to both sides

-4x=x + 15

Subtract x from both sides

-5x=15

X=-3

2y = -3+1

-2y=-2

Y=1

(-3,1)