Question

1-2+3-4+.......+199-200+100

Answer 1

(1 - 2) + (3-4) + .... + (199-200) + 100

= (-1) + (-1) + ......+ (-1) + 100 (có 100 số (-1)

= (-1) . 100 + 100

= 1 + 100 = 101

Tick nha!!

Answer 2

= (1-2) + (3-4) +....+ ( 199-200) +100

= -1 + (-1) +....+ (-1) + 100

= (-1) x 100 +100

= -100 +100

=0