问题 填空题
a
b
=
4
5
,则
a
2a+b
=______.
答案

a
b
=
4
5

b
a
=
5
4

2a+b
a
=2+
b
a
=2+
5
4
=
13
4

a
2a+b
=
4
13

故答案是:

4
13

选择题
多项选择题