# Math Help - summation?

1. ## summation?

Make up five data points and show that Σ(X+C) = ΣX + NC, where C is any constant (e.g., 4) and N is the number of data points. i don't get it.

2. $\sum_{i=1}^n(a_i +C)$

means

$(a_1 +C)+(a_2 +C)+(a_3 +C)+(a_4 +C)+\cdots +(a_n +C)$

$= (a_1 +a_2+a_3+a_4 +\cdots +a_n)+(C+C+C+\cdots +C)$

$=\sum_{i=1}^n(a_i) +nC$

3. Originally Posted by matheagle
$\sum_{i=1}^n(a_i +C)$

means

$(a_1 +C)+(a_2 +C)+(a_3 +C)+(a_4 +C)+\cdots +(a_n +C)$

$= (a_1 +a_2+a_3+a_4 +\cdots +a_n)+(C+C+C+\cdots +C)$

$=\sum_{i=1}^n(a_i) +nC$
sorry, i still don't get what you mean.