Question

Tìm số nguyên x và y biết:  \(\dfrac{x}{4}\)-\(\dfrac{1}{y}\)=\(\dfrac{1}{2}\)

Answer 1

\(\dfrac{x}{4}-\dfrac{1}{y}=\dfrac{1}{2}\)

=>\(\dfrac{xy-4}{4y}=\dfrac{1}{2}\)

=>xy-4=2y

=>xy-2y=4

=>y(x-2)=4

=>\(\left(x-2;y\right)\in\left\{\left(1;4\right);\left(4;1\right);\left(-1;-4\right);\left(-4;-1\right);\left(2;2\right);\left(-2;-2\right)\right\}\)

=>\(\left(x;y\right)\in\left\{\left(3;4\right);\left(6;1\right);\left(1;-4\right);\left(-2;-1\right);\left(4;2\right);\left(0;-2\right)\right\}\)