Câu hỏi của nguyen vu ly na

Question

tìm số tự nhiên x sao cho:

(3X+16)chia hết cho (x+2)

Hà Hoàng Thịnh · Accepted Answer

( 3x + 16 )$⋮$( x + 2 )

$\Rightarrow$3x + 16 = 3 ( x + 2 ) +10

$\Rightarrow$10$⋮$( x + 2 )

$\Rightarrow$x + 2 $\in$$\left\{1;2;5;10\right\}$

$\Rightarrow$x$\in\left\{0;3;8\right\}$

Câu trả lời:

( 3x + 16 )$⋮$( x + 2 )

$\Rightarrow$3x + 16 = 3 ( x + 2 ) +10

$\Rightarrow$10$⋮$( x + 2 )

$\Rightarrow$x + 2 $\in$$\left\{1;2;5;10\right\}$

$\Rightarrow$x$\in\left\{0;3;8\right\}$

A lovely girl · Answer

$\left(3x+16\right)⋮x+2$

$\Rightarrow3\left(x+2\right)+10⋮x+2$

$\Rightarrow10⋮x+2\Rightarrow x+2\inƯ\left(10\right)$

Mà $Ư\left(10\right)=\left\{1;2;5;10\right\}$

$\Rightarrow x+2\in\left\{1;2;5;10\right\}$

$\Rightarrow x\in\left\{-1;0;3;8\right\}$

Vì $x\in N\Rightarrow x\in\left\{0;3;8\right\}$