Question

thuc hien phep tinh 

m=1+(-2)+3+(-4)+...+(-2016)+2017

Answer 1

m = 1 + ( -2 ) + 3 + ( -4 ) + ....... + ( - 2016 ) + 2017

m = [ 1 + ( - 2 ) ] + [ 3 + ( -4 ) ] + ...... + [ 2015 + ( -2016 ) + 2017

m =    ( -1 ) + ( -1 ) + ...... + ( -1 ) + 2017

         có 1008 số -1

m = ( -1 ) x 1008 + 2017

m = ( -1008 ) + 2017 

, = 1009

Answer 2

Ta có :

m = 1 + ( -2 ) + 3 + ( -4 ) + ....... + ( - 2016 ) + 2017

m = [ 1 + ( - 2 ) ] + [ 3 + ( -4 ) ] + ...... + [ 2015 + ( -2016 ) + 2017

m = ( -1 ) + ( -1 ) + ...... + ( -1 ) + 2017 [ có 1008 số -1 ]

m = ( -1 ) x 1008 + 2017

m = ( -1008 ) + 2017 

m = 1009