9ใใผใธใฎไนไน่กจใฎ3ใฎๆฎตใฎๆฐ3, 6, 9,
ใฏ
3=3ร1, 6=3ร2, 9=3ร3,
ใฎใใใซ,3ร(่ช็ถๆฐ)ใฎๅฝขใง่กจใใใใ, 3ใฎๅๆฐใงใ
3ใซ่ฒ ใฎๆดๆฐใ0ใใใใๅฝขใง่กจใใๆฐใ, 3ใฎๅๆฐใง
ใใใจ่ใใใใใจใใฐ,=3,-6,-9, โฆ ใ0ใ
2ใฎๅๆฐใงใใใ
nใๆดๆฐใฎใจใ,3n ใฏ3ใฎๅๆฐใ่กจใใฆใใใ