Question

Bài 11: Tìm x, y nguyên sao cho:   a/ x(y – 3) = 15;                  b/  xy – 2y + 3(x – 2) = 7

Answer 1

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

hay \(\left(x,y\right)\in\left\{\left(1;18\right);\left(3;8\right);\left(5;6\right);\left(15;4\right);\left(-1;-12\right);\left(-3;-2\right);\left(-5;0\right);\left(-15;2\right)\right\}\)