Question

1, -7 \(⋮\) 2n + 1

2, -11 \(⋮\) 2n + 5

Answer 1

a/ \(-7⋮2n+1\)

\(\Leftrightarrow2n+1\inƯ\left(-7\right)\)

\(\Leftrightarrow\left[{}\begin{matrix}2n+1=1\\2n+1=7\\2n+1=-1\\2n+1=-7\end{matrix}\right.\) \(\Leftrightarrow\left[{}\begin{matrix}n=0\\n=3\\n=-1\\n=-3\end{matrix}\right.\)

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b/ \(-11⋮2n+5\)

\(\Leftrightarrow2n+5\inƯ\left(-11\right)\)

\(\Leftrightarrow\left[{}\begin{matrix}2n+5=1\\2n+5=11\\2n+5=-1\\2n+5=-11\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}n=-2\\n=3\\n=-3\\n=-8\end{matrix}\right.\)

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