Question

tìm x,y thuộc z saocho 

xy+3x-2y=11

Answer 1

mk ko bt

Answer 2

\(xy+3x-2y=11\)

\(\Leftrightarrow x\left(y+3\right)-2y=11\)

\(\Leftrightarrow x\left(y+3\right)-2y-6=5\)

\(\Leftrightarrow x\left(y+3\right)-2\left(y+3\right)=5\)

\(\Leftrightarrow\left(x-2\right)\left(y+3\right)=5\)

\(\Rightarrow\left(x-2\right)\left(y-3\right)\inƯ\left(5\right)=\left\{1;-1;5;-5\right\}\)

Ta có bảng sau:

x + 3	1	-1	5	-5
y - 2	5	-5	1	-1
x	-2	-4	2	-8
y	7	-3	-1	1

Vậy \(\left(x;y\right)\in\left\{\left(-2;7\right)\left(-4;3\right);\left(2;-1\right);\left(8;-1\right)\right\}\)