xy + 2x - y = 9
<=> xy + 2x - y - 2 = 7
<=> x(y + 2) - (y + 2) = 7
<=> (x - 1)(y + 2) = 7
| x - 1 | 1 | -1 | 7 | -7 |
| y + 2 | 7 | -7 | 1 | -1 |
| x | 2 | 0 | 8 | -6 |
| y | 5 | -9 | -1 | -3 |
Vậy...
Tim x,y thuoc Z biet
a, xy - 2x - 3y = 5
b,5xy - 5x + y = 5
c,x + xy + y = 9
tim x,y thuoc N (2x+1)(y+2)=10
tim x,y,z thuoc Z biet /2x-4/+/y+2/+/2x+3y-z/=0
(2x-1)(3y-2)=27 tim x y biet x y thuoc n
Tim x,y thuoc N thoa(2x) nhan (y+1)=12
tim x;y thuoc Z
(2x-1)(y+4)=10
a, [2x-1].[4y-2]=-42
b, x+xy+y=9
c, xy-2x-3y=5
Tim x,y thuoc N biet
(2x-1).(y+2)=15
tim x, y thuoc Z biet
(2x-1)*(y+4)=11
