Question

Tìm số tự nhiên x, y biết:

a) (x - 2). y = 3

b) (2 - x) . (y - 4) = 8

Answer 1

a: \(\Leftrightarrow\left(x-2;y\right)\in\left\{\left(1;3\right);\left(3;1\right);\left(-1;-3\right);\left(-3;-1\right)\right\}\)

=>\(\left(x,y\right)\in\left\{\left(3;3\right);\left(5;1\right);\left(1;-3\right);\left(-1;-1\right)\right\}\)

b: =>(x-2)(y-4)=-8

=>\(\left(x-2;y-4\right)\in\left\{\left(1;-8\right);\left(-8;1\right);\left(2;-4\right);\left(-4;2\right);\left(8;-1\right);\left(-1;8\right);\left(-2;4\right);\left(4;-2\right)\right\}\)

=>\(\left(x,y\right)\in\left\{\left(3;-4\right);\left(-6;5\right);\left(4;0\right);\left(-2;6\right);\left(10;3\right);\left(1;12\right);\left(0;8\right);\left(-2;6\right)\right\}\)