Question

[Nguyễn Gia Bảo]

tìm x

2x+10 chia hết cho x+1

2x+10 chia hết cho x-1

3x+10 chia hết cho x+1

Answer 1

[Nữ ❣√ Hoàng ♛⇝ Selfia ✔♫]

\(2x+10⋮x+1\)

\(\Rightarrow2x+2+8⋮x+1\)

\(\Rightarrow2\left(x+1\right)+8⋮x+1\)

\(\Rightarrow x+1\inƯ\left(8\right)=\left\{\pm1;\pm2;\pm4;\pm8\right\}\)

\(x\in\left\{0;1;-2;\pm3;-5;7;-9\right\}\)

Answer 2

[Nữ ❣√ Hoàng ♛⇝ Selfia ✔♫]

\(2x+10⋮x-1\)

\(\Rightarrow2x-2+12⋮x-1\)

\(\Rightarrow2\left(x-1\right)+12⋮x-1\)

\(\Rightarrow x-1\inƯ\left(12\right)=\left\{\pm1;\pm2;\pm3;\pm4;\pm6;\pm12\right\}\)

x - 1 = 1 => x = 2

x -1 = -1 => x = 0 

... tg tự