Tim x, y thuoc Z, biet:
x.y+x+y+1=-3
tim x,y biet x.y +2x=3
tim x, y thuoc Z biet : x.y - 2.x - 3.y = 5 ( trinh bay nha )
Tim x,y biet x.y.(x+y)=456789
tim x va y biet x.y =x+y
tim x va y biet x.y=x+y
tim x, y thuoc Z biet x+y -x.y = 7
Tim x ,y biet
x.y-2x+3y=3
tim x,y thuoc N, biet x.y+2.x+y-13=0