Question

(x-3) chia hết cho (x+2)

Answer 1

\(x-3⋮x+2\)

=>\(x+2-5⋮x+2\)

=>\(x+2\inƯ\left(-5\right)\)

=>\(x+2\in\left\{1;-1;5;-5\right\}\)

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

Answer 2

Ta  có:

x-3⋮x+2

<=>x-2+1⋮x+2

Mà  1⋮x+2

x+2 là Ư(1)

x+2∈{1;-1}

x∈{-1;-3}

Vậy x∈{-1;-3}