Sum of first n natural numbers = n(n+1)/2
Sum of the squares of first n natural numbers = n(n+1)(2n+1)/6
Sum of the cubes of first n natural numbers = [n(n+1)/2]2
Sum of first n natural odd numbers = n2
Average = (Sum of items)/Number of items
(a + b)^1 = a + b
(a + b)^2 = a2 + 2ab + b2
(a + b)^3 = a3 + 3a2b + 3ab2 + b3
(a + b)^4 = a4 + 4a3b + 6a2b2 + 4ab3 + b4 ...and so on...
a2 - b2 = (a - b)(a + b)
Note : ^ denotes to the power of something here
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