11

---

18

B

29(15−34)−15(29−34)=29.15−29.34−15.29+15.3429(15−34)−15(29−34)

=29.15−29.34−15.29+15.34

=(29.15−15.29)+(15.34−29.34)

=(29.15−15.29)+(15.34−29.34)

=15.34−29.34

=15.34−29.34

=34(15−29)

=34.(−14)

=−34.14

=−476

D

D

{0;120;240;360;480}

20.40: 2= 400 cm²

educational

1.D

2.D