Объяснение:

1

EF=MN-(ME+FN) =12-(3+4)=12-7=5

2

BD=AB-(AC+CD)=15-(6+7)=15-13=2

3

KL-LP=5

KL=5+LP

KP=KL+LP

21=5+LP+LP

21=5+2LP

2LP=21-5

2LP=16

LP=8

KL=5+8=13

4

SR-RT=4

SR=4+RT

ST=SR+RT

36=4+RT+RT

36=4+2RT

2RT=36-4

2RT=32

RT=16

SR=4+16=20

5

EM=3MF

EF=EM+MF

EF=3MF+MF

36=4MF

MF=36:4

MF=9

EM=3×9=27

6

AC=4BC

AB=AC+BC

AB=4BC+BC

15=5BC

BC=3

AC=4×3=12

7

MK=KN-12

MN=MK+KN

24=KN-12+KN

24=2KN-12

2KN=24+12

2KN=36

KN=18

MK=18-12=6

8

BC=30

CD-BD=20

CD=20+BD

BC=BD+CD

BC=BD+20+BD

30=2BD+20

2BD=30-20

2BD=10

BD=5

CD=20+5=25