问题 填空题
已知
a
b
=
c
d
=
e
f
=
5
7
,则
2a-c+7e
2b-d+7f
=______,
2a-c
2b-d
=______.
答案

a
b
=
c
d
=
e
f
=
5
7

2a
2b
=
c
d
=
7e
7f

2a-c+7e
2b-d+7f
=
5
7

2a-c
2b-d
=
5
7

故答案为:

5
7
5
7

填空题
单项选择题