Chắc đề bài thế này phải ko:
Tính x biết \(2x-5\) là \(Ư\left(6\right)\)
BL:
Ta có: \(Ư\left(6\right)=\left\{\pm1;\pm2;\pm3;\pm6\right\}\)
\(\Rightarrow2x-5\in\left\{\pm1;\pm2;\pm3;\pm6\right\}\)
Xét TH:
_ Nếu \(2x-5=1\Rightarrow x=3\)
_ Nếu \(2x-5=-1\Rightarrow x=2\)
_ Nếu \(2x-5=2\Rightarrow x=\frac{7}{2}\)
_ Nếu \(2x-5=-2\Rightarrow x=\frac{3}{2}\)
_ Nếu \(2x-5=3\Rightarrow x=4\)
_ Nếu \(2x-5=-3\Rightarrow x=1\)
_ Nếu \(2x-5=6\Rightarrow x=\frac{11}{2}\)
_ Nếu \(2x-5=-6\Rightarrow x=\frac{-1}{2}\)
Vậy \(x\in\) \(\left\{3;2;\frac{7}{2};\frac{3}{2};4;1;\frac{11}{2};\frac{-1}{2}\right\}\).
