Question

-1+2-3+4-5.......-99+100 = ?

Answer 1

-1+2-3+4-5.....-99+100 = - (1+3+5+7.........+99) + (2+4+6+8.......+100)

→ -(1+3+5+7.....+99) = - (50²) { sum of odd numbers = n²}

                            = 2500

→(2+4+6+8...+100) = 2×(1+2+3+........+100)

                           = 2×55=110

Sum = 2500+110 = 2610

Hope it helps u