posted by mark .
solve and explain please
They cannot be solved. Add 2x to both sides of the second equation in the pair to see this.
You have a typo in the last equation. If it is -y, then they are unsolvable. If positive y, then add the two equations to get 8x = 4 or x = 4/8 = 1/2
It would help if you proofread your questions before you posted them.
and show work