[tex]\displaystyle \left \{ {{x-2y=5} \atop {3x+8y=1}} \right.\\ \\\left \{ {{x=5+2y} \atop {3x+8y=1}} \right.\\ \\3(5+2y)+8y=1\\y=-1\\x=5+2*(-1)\\x=3\\(x,y)=(3,-1)[/tex]