Question

(2x + 1).(2y - 5) = 15

Answer 1

\(\Leftrightarrow\left(2x+1,2y-5\right)\in\left\{\left(1;15\right);\left(15;1\right);\left(-1;-15\right);\left(-15;-1\right);\left(3;5\right);\left(5;3\right);\left(-3;-5\right);\left(-5;-3\right)\right\}\)

\(\Leftrightarrow\left(x,y\right)\in\left\{\left(0;10\right);\left(7;3\right);\left(-1;-5\right);\left(-8;2\right);\left(1;5\right);\left(2;4\right);\left(-2;0\right);\left(-3;1\right)\right\}\)