Ta có: \(B=2-4-6+8+10-12-14+...-2014+2016+2018-2020\)
\(=\left(2-4-6+8\right)+\left(10-12-14+16\right)+...+\left(2010-2012-2014+2016\right)+\left(2018-2020\right)\)
\(=2018-2020=-2\)
Tính nhanh tổng sau :
2+4-6-8+10+12-14-16+18+...+2012-2014-2016+2018+2020
1+2-3-4-5+6+7-8-9-10+11+12-13-14-15+...+2011+2012-2013-2014-2015+2016+2017-2018-2019-2020 giup mik v
( 2020 - 2018 ) + ( 2016 - 2014 ) + ..........+ ( 16 - 14 ) + (12 - 10 ). Tính giá trị biểu thức. Giúp mình điiiii plssss
6-8-10-12+14+16-18-20-22+24+...+2016-2018-2020-2022+2024
6-8-10-12+14+16-18-20-22+24+....+2016-2018-2020-2022+2024
2 + (- 4) + 6 + (-8) + 10 + ( -12) +......+2014 + ( - 2016) + 2018
Tính A= 2020-2018+2016-2014+...+8-6+4-2
a = 2- 4-6 + 8 +10 - 12 - 14 + 16 +.... + 2018 - 2020+2024
ai lm dc like luôn
2+4-6-8+10+12-14-16+18+...+2010+2012-2014-2016
giúp mình nhé các bạn
