Question

Bài 4*: Tìm x, y  Z , biết :
a) x . y = 12
b) (x + 1).(y + 3) = 6

Answer 1

a: Ta có: xy=12

nên \(\left(x,y\right)\in\left\{\left(1;12\right);\left(-1;-12\right);\left(12;1\right);\left(-12;-1\right);\left(2;6\right);\left(-2;-6\right);\left(6;2\right);\left(-6;-2\right);\left(3;4\right);\left(4;3\right);\left(-3;-4\right);\left(-4;-3\right)\right\}\)