Math Help - arithmetic sequence

1. arithmetic sequence

Find the sum of the even integers between
-50 and 200 including them, that is,
-50+(-48)+(-46)+....+198+200
Write down and use the correct formula.

2. Hello, Steph07!

Find the sum of the even integers between -50 and 200, inclusive.
That is: . $\text{-}50+(\text{-}48)+(\text{-}46)+ \hdots +198+200$

Write and use the correct formula.

This is an arithmetic series with:
. . first term $a = -50$, common difference $d = 2$, and $n=126$ terms.

The sum is: . $S \;=\;\tfrac{n}{2}[2a + (n-1)d] \;=\;\tfrac{126}{2}[2(-50) + 125(2)] \;=\;9450$

3. thank u

thank you so much!! ur awesome!