What is the substitution of - 6x-8y=-20 and x+6y=-6

x=-4/3y+10/3 and x=-6-6y

Substitution doesn't work for this, but elimination does.

-6x-8y=-20 + 6 (x+6y=-6)

-6x-8y=-20 + 6x+36y=-36

-6x and 6x cancel each other, add - 8 and 36 to get 28, and - 20 and - 36 to get - 56.

28y=-56

divide by 28 on both sides.

Y = - 2

Then substitute y into one of the equations.

x+6 (-2) = -6

x-12=-6

x=6

The ordered pair is (6,-2).