\(1+\left(-2\right)+\left(-3\right)+4+5++...+97+\left(-98\right)+\left(-99\right)+100\)
\(=\left[1+\left(-2\right)\right]+\left[\left(-3\right)+4\right]+...+\left[-99+100\right]\)
\(=-1+\left(-1\right)+\left(-1\right)+...+\left(-1\right)\)
\(=-1.50\)
\(=-50\)
1 + ( - 2 ) + ( - 3 ) + 4 + 5 + ( - 6 ) + ( -7 ) + ........... + 97 + ( - 98 ) + ( - 99 ) + 100
= [ 1 + ( - 2 ) ] + [ 4 + ( - 3 ) ] + ........+ [97 + ( - 98 ) + (- 99 ) + 100 )
= - 1 + 1 + ....... + ( - 1 ) + 1
Ta có: Tổng hai số đối sẽ bằng 0
<=>
1 + ( - 2 ) + ( - 3 ) + 4 + 5 + ( - 6 ) + ( -7 ) + ........... + 97 + ( - 98 ) + ( - 99 ) + 100 = 0
