Ответ:

Пошаговое объяснение:

N1

1)

x/5 = 4/20

х = 5 * 4 / 20

х = 20/20

х = 1

2)

6/х = 18/30

х = 6 * 30 / 18

х = 180/18

х = 10

3)

1/3 = 7/х

х = 3 * 7 / 1

х = 21/1

х = 21

4)

42/78 = х/13

х = 42 * 13 / 78

х = 546/78

х = 7

N 2

1) 1/2 = (1*18)/(2*18) = 18/36

2) 2/6 = (2*6)/(6*6) = 12/36

3) 5/9 = (5*4)/(9*4) = 20/36

4) 1/12 = (1*3)/(12*3) = 3/36

5) 7/18 = (7*2)/(18*2) = 14/36

N 3

1) 2/4 = 1/2

3) 6/20 = 3/10

5) 42/98 = 3/7

7) 60/156 = 5/13

2) 7/28 = 1/4

4) 24/56 = 3/7

6) 18/81 = 2/9

8) 300/450 = 2/3