Question

(1+2+3+..............+2015)(20142014x2016-20162016x2014)

giúp mình zới!!!! mình tích cho ^.^

Answer 1

(1+2+3+..............+2015)(20142014x2016-20162016x2014)

Đặt A=(1+2+3+.........+2015)

Ta có: = A.[20142014x(2014+2)-(20142014+2)x2014]

= A.[2014x2014+2014x2-20142014x2014-2014x2]

= A.0

= 0

Vậy tích trên bằng 0

Answer 2

 

(1+2+3+..............+2015)(20142014x2016-20162016x2014)

=(1+2+3+..............+2015)[(20140000+2014)x2016-(20160000+2016)x2014]

=(1+2+3+..............+2015)(2014.2016.10000+2014.2016-2014.2016.10000-2014.2016)

=(1+2+3+..............+2015).0

=0