Question

What is the value of the summation ∑i=1n(2i2+i−8)?

2(n + 1)(2n + 1) + 3(n + 1) − 48

n6 [2( n + 1)(2 n + 1) + 3( n + 1) − 48]

(n + 1)(2n + 1) + 3(n+1)2 − 48

n(2n+1)6 + n(n+1)2 − 48n