Question

14 chia hết cho ( 2 . x + 4 )

Answer 1

\(\Leftrightarrow2x+4\inƯ\left(14\right)=\left\{1;2;7;14\right\}\\ \Leftrightarrow2x\in\left\{-3;-2;3;10\right\}\\ \Leftrightarrow x\in\left\{-\dfrac{3}{2};-1;\dfrac{3}{2};5\right\}\)

Answer 2

VÌ 14⋮(2x+4)

⇒2x+4∈Ư(14)

⇒2x+4∈{1;2;7;14}

⇒2x∈{3;10} (x∈N)

⇒x∈{\(\dfrac{3}{2}\);5}

Mà x∈N

⇒x=5

Vậy x=5