No solution.
You can deduct this by doing the elimation method. Multiply one of the equations by - 1 and then combine like terms (x's with x's, y's with y's, integers with integers). You'll set 0x + 0y = 15 or 0x + 0y = - 15 OR 0 = 15, 0 = - 15 which is not a true statement. Thus, no solution.
