S2

tim y,biet

6chia het 2y + 1

H24
1 tháng 11 2018 lúc 21:22

\(6⋮2y+1\)

\(\Rightarrow2y+1\inƯ\left(6\right)=\left\{-6;-3;-2;-1;1;2;3;6\right\}\)

\(\Rightarrow2y\in\left\{-7;-4;-3;-2;0;1;2;5\right\}\)

\(\Rightarrow y\in\left\{\frac{-7}{2};-2;\frac{-3}{2};-1;0;\frac{1}{2};1;\frac{5}{2}\right\}\)

Bình luận (0)
ND
1 tháng 11 2018 lúc 21:25

=> 2y+1 \(\inƯ\left(6\right)\)

=>  2y+1 \(\in\left\{\pm1,\pm2,\pm3,\pm6\right\}\)

=>2y\(\in\left\{-7,-4,-3,-2,0,1,2,5\right\}\)

=>y\(\in\left\{-2,-1,0,1\right\}\)(vì y thuộc Z)

Bình luận (0)