Question

tính tổng sau:a=1/2+1/4+1/8+1/16[tổng trên có 10 số hạng

Answer 1

a = 1/2 + 1/4 + 1/8 + 1/16

= ( 1 - 1/2 ) + ( 1/2 -1/4 ) + ( 1/4 - 1/8 ) + ... + ( 1/512 - 1/1024 )

= 1 - 1/1024

= 1023/1024

Answer 2

a = 1/2+1/4+1/8+1/16

= (1 - 1/2) + (1/2 -1/4) + (1/4 - 1/8) + ... + (1/512 - 1/1024).

= 1 - 1/1024

= 1023/1024