6c-8 would be the answer to your question
When the multiples of the equations in a system is added or subtracted, the resulting equation together with any of the original equation will result in the same answer.
Hence, the system of equations
x + 4y = 2
7x = 14
will also have a solution of (2, 0).
This was written using the associative property.
(7+5) +2 equals 12+2 which equals 14.
7 +(5+2) equals 7+7 which equals 14.
Do you need a picture of one??