Aru tiktiwin-agi ɣef uselkim-ik:  2 𝑛𝑛 𝑛𝑛𝑥𝑥 𝑛𝑛(𝑛𝑛−1)𝑥𝑥  (1+𝑥𝑥) = 1+ 1! + 2! +⋯ 2 −3±√3 −4𝑎𝑎𝑎𝑎  CH CH OH+PCI CH CH CI+POC13 +HCI 𝑥𝑥 =3 22𝑎𝑎 5 3 2  A ∩ B = C → C ⊂ A ∪ B 4-Alaɣmu wis rebɛa :