−4x + y = 6−5x − y = 21
assuming x=x and y=y in both equationsadd them together-4x+y=6-5x-y=21 +-9x+0y=27-9x=27divide by 9-x=3multiply -1x=-3subsiutte-4x+y=6-4(-3)+y=612+y=6subtract 12y=-6x=-3y=-6the soultion set is in (x,y) form(-3,-6)