201920203422_11
______________________________________________________
14
f
1
2
3
e
1
24
f
2MxyF20lx8
3MxyF50lx
4
1Mxy30lx
M
1
12mx2my22y1m
A
B
C3
D1
2MF02ly301
M__________
1
2
2y24xAAB2
1x2
Ay28x
By28x
Cy24x
Dy2
4x
34
f
2l14x3y60l2x1y24x
Pl1l2
A2
B3
C
D3176
31PF2bb1P
44
fr