Double the first equation and add to the second: 6x-8y=-20 added to 5x+8y=-2 gives 11x=-22, so x=-2. Substitute this vale of x in either equation. We'll choose the first equation: -6-4y=-10 can also be written 6+4y=10, from which y=1. These values, x=-2 and y=1, satisfy both original equations. There is just one solution.