Question

[0o0_Đừng_Nhìn_Mình_0o0]

Tim cac cap so nguyen x,y

a,x . ( y - 3 ) = -12

b,xy - 3x - y = 0

c,xy + 2x + 2y = -16

Answer 1

[Nguyễn Xuân Anh]

a,\(x\left(y-3\right)=-12=-1.12=-2.6=...\)

y-3	12	6	4	3	2	1	-1	-2	-3	-4	-6	-12
x	-1	-2	-3	-4	-6	-12	12	6	4	3	2	1
y	15	9	7	6	5	4	2	1	0	-1	-3	-9

Vậy có 12 cặp số nguyên (x;y) là: (-1;15);(-2;9);(-3;7);(-4;6);(-6;5);(-12;4);(12;2);(6;1);(4;0);(3;-1);(2;-3);(1;-9)

b,\(xy-3x-y=0\)

\(\Leftrightarrow\left(x-1\right)\left(y-3\right)=3=1.3=3.1=-1.-3=-3.-1\)

x-1	-3	-1	1	3
y-3	-1	-3	3	1
x	-2	0	2	4
y	2	0	6	4

Vậy........

c, \(xy+2x+2y=-16\)

\(\Leftrightarrow\left(x+2\right)\left(y+2\right)=-12=-1.12=-2.6=...\)

x+2	-12	-6	-4	-3	-2	-1	1	2	3	4	6	12
y+2	1	2	3	4	6	12	-12	-6	-4	-3	-2	-1
x	-14	-8	-6	-5	-4	-3	-1	0	1	2	4	10
y	-1	0	1	2	4	10	-14	-8	-6	-5	-4	-3

Vậy.......

Answer 2

[Không Tên]

a,\(x\left(y-3\right)=-12=-1.12=-2.6=...\)

y-3	12	6	4	3	2	1	-1	-2	-3	-4	-6	-12
x	-1	-2	-3	-4	-6	-12	12	6	4	3	2	1
y	15	9	7	6	5	4	2	1	0	-1	-3	-9

Vậy có 12 cặp số nguyên (x;y) là: (-1;15);(-2;9);(-3;7);(-4;6);(-6;5);(-12;4);(12;2);(6;1);(4;0);(3;-1);(2;-3);(1;-9)

b,\(xy-3x-y=0\)

\(\Leftrightarrow\left(x-1\right)\left(y-3\right)=3=1.3=3.1=-1.-3=-3.-1\)

x-1	-3	-1	1	3
y-3	-1	-3	3	1
x	-2	0	2	4
y	2	0	6	4

Vậy........

c, \(xy+2x+2y=-16\)

\(\Leftrightarrow\left(x+2\right)\left(y+2\right)=-12=-1.12=-2.6=...\)

x+2	-12	-6	-4	-3	-2	-1	1	2	3	4	6	12
y+2	1	2	3	4	6	12	-12	-6	-4	-3	-2	-1
x	-14	-8	-6	-5	-4	-3	-1	0	1	2	4	10
y	-1	0	1	2	4	10	-14	-8	-6	-5	-4	-3

Vậy.......