Question

belabel

help me please 🙏🙏

a. 2 +4 +6+ ..+ 2n = n(n + 1)
b. 1+4 +7+ ..+ (3n – 2) = n(3n-1)
c. (1.1!) + (2.2!) + (3.3!) +
d. 1.2+2.3+3.4+ +n(n + 1) =
e. 2(1 + 3+32 + 33 + ...+ 3"-1) = 3" – 1
2
+ (n. n!) = (n + 1)! – 1
n(n+1)(n+2)
...
...
%3D
%3D