Answer
Sum of first 50 terms = 2350
Work Step by Step
Given sequence = -2, 0, 2, 4...................
This is a arithmetic sequence then
first term $a_{1}$ = -2
common difference (d) = 4 - 2 = 2
$50^{th}$ term = -2 + (50 - 1)2 = -2 + 100 -2 = 96
Sum of first 50 terms = $\frac{50}{2}$( $a_{1}$ + $a_{50}$)
= $\frac{50}{2}$( -2 + 96)
= 25$\times$94 = 2350
