20
A. -1 dan 7, B. x = 3, C. (3,16), D. -9 <= y <= 16
13
D
7
A
8
D
15
A
18
B
17
B
9
B
6
D
4
D
14
D
1
C
2
B
3
D
10
hanya (iii)
19
D
11
D
5
A
16
B
12
A