You can plug 2x-5 into the first equation for y since it gives you that y=2x-5. Then, you get 6x+5(2x-5)=7. After distributing the 5, you get 6x+10x-25=7. You can now combine the like terms 6x and 10x. You get 16x-25=7. Then, add 25 to both sides and get 16x=32. You can divide 16 by both sides to leave the x by itself and you get x=2.
x=2
After finding the x, you can plug 2 back into either equation to get your y. If you plug it into the second equation, you get y=2(2)-5=-1