Question

Solve 2+4+6 +⋯ +48−3−5−7 − … −51

WITH EXPLANATION PLEASE!!!

Answer 1

-75

Explanation:

2+4+6+8 ... +48-3-5-7 ... -51

2+4+6+8... = 600

600-3-5-7-9 = -675

-75

Answer 2

-98

Explanation:

Given:

2+4+6 +⋯ +48−3−5−7 − … −51

Find solution:

(2+4+6 +⋯ +48)−(3+5+7+ …+51)

Computation:

an = a + (n-1)d

For

(2+4+6 +⋯ +48)

48 = 2 + (n-1)2

n=22

For

(3+5+7+ …+51)

51 = 3 + (N-1)2

N = 24

Sn = n/2(a+an)

So

22/2(2+48)-24/2(3+51)

550 - 648

-98