1] 75:[2x] = 15:25 2]44:99 = 4:[3x] 3] [5x]:13 = 8:52 4] 10,5:21 = [4x]:20

Поша75:(2х)=15:25

75:(2х)=0.6

2х=75:0.6

2х=125

х=125:2

х=62.5

44:99=4:(3х)

0.44=4:(3х)

3х=4:0.44

3х=9

х=3

(5х):13=8:52

(5х):13=0.15

5х=0.15*13

5х=1.95

х=1.95:5

х=0.39

10.5:21=(4х):20

0.5=(4х):20

4х=20*0.5

х=10:4

х=2.5говое объяснение: