y + 1 thuộc U(7) ; 2x + 3 thuộc U(7)
mà U(7) = {1;7;-1;-7}
suy ra:
| y + 1 | 1 | 7 | -1 | -7 |
| 2x + 3 | 7 | 1 | -7 | -1 |
| y | 0 | 6 | -2 | -8 |
| x | 2 | -1 | -5 | -2 |
vậy có 4 cặp ( x,y ) thỏa mãn (y + 1). (2x + 3) = 7
so cap x;y nguyen thoa man [x+1][x+2]=7 la bao nhieu
so cap so nguyen x,y thoa man 5/x-y/3=1/6 la
Cho x;y la so nguyen sao cho | x | + | y | = 5. So cap so nguyen ( x;y ) thoa man la
so cap so nguyen x,y thoa man dieu kien 3/x+y/3=5/6 la ... cap
so cap x;y thoa man ( y+ 1 ) ( 2x+3 ) =7 la
so cap x;y nguyen thoa man x>y va x/5=7/y la giup mik nhe mik tik cho !
cho 2 so x;y la cac so nguyen sao cho :/x/ +/y/ = 2 so cap (x;y) thoa man la
a, co bao nhieu cap so nguyen ( x,y ) thoa man x + y=1
b. co bao nhieu cap so nguyen ( x,y ) thoa man x.2 + y =1
so cap (x;y) nguyen thoa man (x+1)(y+2)=7
