Tìm số nguyên x sao cho 3x-5 chia hết cho x-1 12/07/2021 Bởi Kaylee Tìm số nguyên x sao cho 3x-5 chia hết cho x-1
$3x – 5 \vdots x – 1$ $\Leftrightarrow 3(x – 3) – 2 \vdots x – 1$ $\Leftrightarrow 2 \vdots x – 1$ $\Leftrightarrow x – 1 \in Ư(2) = \left \{ -2; -1; 1; 2 \right \}$ $\Leftrightarrow x \in \left { -1; 0; 2; 3 \right }$ Bình luận
3x-5⋮ x-1
⇔ 3.( x-1)-2⋮ x-1
⇒ 2⋮ x-1
⇒ x-1∈ Ư( 2)= { -2; -1; 1; 2}
⇒ x∈ { -1; 0; 2; 3}
$3x – 5 \vdots x – 1$
$\Leftrightarrow 3(x – 3) – 2 \vdots x – 1$
$\Leftrightarrow 2 \vdots x – 1$
$\Leftrightarrow x – 1 \in Ư(2) = \left \{ -2; -1; 1; 2 \right \}$
$\Leftrightarrow x \in \left { -1; 0; 2; 3 \right }$