Elgendy In Math

فَأَمَّا الزُّبْدُ فَيَذْهَبُ جُفَاءً وَأَمَّا مَا يَنْفَعُ النَّاسَ فَيَمْكُثُ فِي الْأَرْضِ
الدرس الرابع تانيه ثانوي لغات ⚠️
IMPORTANT EXAMPLE ✅️✅️
A series is the sum of the terms of a sequence.
Example: 2 + 5 + 8 + 11 + …
First term (a₁) = 2
Common difference (d) = 3
Number of terms (n) = 4
Sn=n/2(2a + (n-1)×d)