Question

tim x biet (2x+1)+(2x+2)+...+(2x+2015)=0

Answer 1

Có 2015 số hạng

Tổng là (2x+1+2x+2015).2015:2=0

4x+2016=0

4x=-2016

x=-504

Ủng hộ mk nha

Answer 2

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

=> ( 2x + 2x + .. + 2x ) + ( 1 + 2 + ... + 2015 ) = 0

           2015 số 2x

=> 2x . 2015 + 2031120 = 0

=> 2x . 2015 = 0 - 2031120

=> 2x . 2015 = - 2031120

=> 2x = ( - 2031120 ) : 2015

=> 2x = - 1008

=> x = ( - 1008 ) : 2

=> x = - 504

Answer 3

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

=> ( 2x.2015 ) + { [ 2015.( 2015 + 1 ] : 2 } = 0

=> 4030x + [ ( 2015 . 2016 ) : 2 ] = 0

=> 4030x + ( 4062240 : 2 ) = 0

=> 4030x + 2031120 = 0

=> 4030x = - 2031120

=> x = - 2031120 : 4030 = - 504

Vậy x = - 504