Trả lời nhanh và đúng thì mình k nha

xy-3x-2y=-5

=>xy-3x-2y+6=1

=>x(y-3)-2(y-3)=1

=>(x-2)(y-3)=1

phần còn lại bạn tự làm nốt nha

a.
xy + 3x - 2y - 6 = 5
=>x(y + 3) - 2(y + 3) = 5
=>(x - 2)(y + 3) = 5.
Vì x, y thuộc Z nên x - 2, y + 3 thuộc Z
=> x - 2, y + 3 thuộc ước nguyên của 5
Lập bảng : 

Vậy ......

b. Làm tương tự câu a.

c. Ta có x + y = 3 và x - y = 15
Bài này là tổng hiệu của cấp 1, áp dụng cách làm đó thì ta được số lớn là x = (3 + 15) : 2 = 9
Số bé là y = 9 - 15 = -6

d. Ta có : |x| + |y| = 1
=>|x| = 1 - |y|
Vì |x|, |y| >= 0 và |x| = 1 - |y| nên 0 =< |x|, |y| =< 1
Vì x, y thuộc Z nên x = 0 thì y = 1 hoặc -1 và ngược lại y = 0 thì x = 1 hoặc -1

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a) \(xy+x+2y=5\Leftrightarrow xy+x+2y+2=7\Leftrightarrow\left(y+1\right)\left(x+2\right)=7\)

Vì x,y là số tự nhiên nên \(x,y\in N\)\(x,y\ge0\)\(\Rightarrow y+1\ge1;x+2\ge2\)

Từ đó ta có : 

\(\hept{\begin{cases}x+2=7\\y+1=1\end{cases}\Leftrightarrow\hept{\begin{cases}x=5\\y=0\end{cases}}}\) 

b) \(xy+2x+2y=-16\Leftrightarrow xy+2y+2x+4=-12\Leftrightarrow\left(y+2\right)\left(x+2\right)=-12\)

Lần lượt xét từng trường hợp , ta được : 

(x;y) = (-14; -1) ; (-8 ; 0) ; (-6 ; 1) ; (-5 ;2) ; (-4 ;4)

a) \(\left(x+2\right)\left(y+1\right)=7=1.7=7.1\)

Hoặc \(\hept{\begin{cases}x+2=7\\y+1=1\end{cases}\Leftrightarrow\hept{\begin{cases}x=5\\y=0\end{cases}}}\in N\)

Hoặc\(\hept{\begin{cases}x+2=1\\y+1=7\end{cases}}\Leftrightarrow\hept{\begin{cases}x=-1\notin N\\y=6\end{cases}}\)

Vậy \(\left(x;y\right)=\left(5;0\right)\)

b)\(\left(x+2\right)\left(y+2\right)=-1.12=-12.1=-2.6=-6.2=-3.4=-4.3\)

tương tự giải 6 TH là được

Lời giải:

$xy-x+2y=2$

$\Rightarrow (xy-x)+(2y-2)=0$

$\Rightarrow x(y-1)+2(y-1)=0$

$\Rightarrow (x+2)(y-1)=0$

$\Rightarrow x+2=0$ hoặc $y-1=0$

$\Rightarrow x=-2$ hoặc $y=1$

ko biết

a) pt <=> (2x-1)(2y+3)=7

TH1: 2x-1=7 và 2y+3=1

<=> x = 4 và y = -1

TH2: 2x - 1 = -7 và 2y + 3 = -1

<=> x = -3 và y = -2

TH3: 2x-1=1 và 2y+3=7

<=> x = 1 và y=2

TH4: 2x-1=-1 và 2y+3=-7

<=> x=0 và y=-5

b) pt <=> (x-3)(y+4)=19

TH1: x - 3=1 và y+4=19

<=> x=4 và y=15

TH2: x-3=-1 và y+4=-19

<=> x=2 và y=-23

TH3: x-3=19 và y+4=1

<=> x=22 và y=-3

TH4: x-3=-19 và y+4=-1

<=> x=-16 và y=-5