\(\left(y+2\right)x+\left(y+2\right)=15\Leftrightarrow\left(y+2\right)\left(x+1\right)=15\)
| x+1 | 1 | 3 | 5 |
| y+2 | 15 | 5 | 3 |
| x | 0 | 2 | 4 |
| y | 13 | 3 | 1 |
tim x ,y thuoc N biet x.y + 2.x +y-13=0
Tim x,y thuoc tap N biet
12.x.y-9.y+20.x=2595
tim x, y thuoc Z biet : x.y - 2.x - 3.y = 5 ( trinh bay nha )
tim x, y thuoc Z biet x+y -x.y = 7
Tim x, y thuoc Z, biet:
x.y+x+y+1=-3
Tim x, y thuoc N, biet:
a) 7 chia het cho (x+1)
b) x.y= 36 va x<y
c) (2n+2) chia het cho (x+2)
Cho A thuoc {0.1.2.3.4.5.6.7.8.9.10} biet A co hon 1 phan tu neu x,y,z thuoc A va x<y<z thi z =x.y tim A
Tim x, y thuoc Z biet : | x-2| + (x-y+1)^2 =0
tim x,y thuoc z biet (x-2).(y+12)<0