(1+1/2)+(2+1/4)+…+(n+1/2n)=_.

问题描述:

(1+

1
2
)+(2+
1
4
)+…+(n+
1
2n
)=______.

(1+

1
2
)+(2+
1
4
)+…+(n+
1
2n
)
=(1+2+3+…+n)+(
1
2
+
1
22
+
1
23
+…+
1
2n
)

=
n(n+1)
2
+
1
2
(1−(
1
2
)n)
1−
1
2

=
n(n+1)
2
+1−
1
2n

故答案为:
n(n+1)
2
+1−
1
2n