Question

Tìm cặp số nguyên x,y sao cho: xy-3x+y=-4

Answer 1

xy-3x+y=-4

=>x(y-3)+y-3=-4-3

=>(x+1)(y-3)=-7

=>\(\left(x+1;y-3\right)\in\left\{\left(1;-7\right);\left(-7;1\right);\left(-1;7\right);\left(1;-7\right)\right\}\)

=>\(\left(x;y\right)\in\left\{\left(0;-4\right);\left(-8;4\right);\left(-2;10\right);\left(0;-4\right)\right\}\)