Symbolic Index /sym/ea4bfa
id=1 · host=au.commstar.world · 2026-10-20 14:44Z
∑_{k=1}^{n} k = n(n+1)/2
∑_{k=1}^{n} k = n(n+1)/2
244K
det| 2 7 ; 7 3 | = -43
52K
det| 12 5 ; 4 13 | = 136
det| 7 4 ; 4 8 | = 40
90K
H₂SO₄ + 2NaOH → Na₂SO₄ + 2H₂O
Fe₂O₃ + 3CO → 2Fe + 3CO₂
137K
∑_{k=1}^{n} k = n(n+1)/2
197K