Question

2+4+6+8+...+2500=x.(x+1)

Answer 1

2 + 4 + 6 + 8 + ... +  2500 (1250 số hạng )

=( 2 +2500) x 1250:2

=1563750

x. ( x + 1) = 1563750=1250 .1251

vậy x = 1250

Answer 2

2 + 4 + 6 + 8 + ... + 2500 = x.(x + 1)

=> 2.(1 + 2 + 3 + 4 + ... + 1250) = x.(x + 1)

=> 2.(1 + 1250).1250:2 = x.(x + 1)

=> 1250.1251 = x.(x + 1)

=> x = 1250

Answer 3

2 + 4 + 6 + 8 + ... +  2500 (1250 số hạng )

=( 2 +2500) x 1250:2

=1563750

x. ( x + 1) = 1563750=1250 .1251

vậy x = 1250

Answer 4

Ta có: 2+4+6+8+...+2500 = (2500+2) . [(2500-2):2+1] : 2 = 2502 .1250 : 2 = (2502:2).1250 = 1251 . 1250

Mà 2+4+6+8+...+2500 = x.(x+1)

=> x.(x+1) = 1250 . 1251 => x=1250