DL
10 tháng 1 2022 lúc 8:10
\(\left(x-1\right)^2=\dfrac{1}{2}=3,5\)
\(\left(x-1\right)^2-\dfrac{1}{2}=\dfrac{7}{2}\)
\(\left(x-1\right)^2\) \(=\dfrac{7}{2}+\dfrac{1}{2}=4=\pm\left(2\right)^2\)
\(\text{Vậy }x-1=2\)
\(x\) \(=2+1=3\)
\(\text{hoặc }x-1=-2\)
\(x\) \(=\left(-2\right)+1=-1\)
\(\Rightarrow x\in\left\{3;\left(-1\right)\right\}\)
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