first because 5x+5y=0 you can factor the 5 from equation so: 5(x+y)=5(0) => x+y=0 and by solving for x using elimination method -8x+y=36 x+y=0 by subtracting both x and y we get -9x=36 => x=-4 by inputing x into the "x+y=0" equation we get: -4+y=0 => y=4
