1.{1,2}
2.2π
3.14
4.1/3
5. {x丨1≤x≤2}
6.y=x²+x
7.-4
8.10
9.{2,4}
10.18跟3
11.y=x
12.16/9
13.跟2/2
14.1
15.a=0.3
16.16
17.x+y=0