Step-by-step explanation:

1. 6:9: : x :21

6/9 = x/21

x= (6×21)/9

x= 14

Do the next 2 questions yourself.

Step-by-step explanation:

1. 6:9: : x :21

6/9 = x/21

2/3 =x/21

2×21 = 3x

x = 2×21 /3

x = 14

2. 4:x: :9:24

4/x = 9/ 24

4/x = 3 /8

4×8=3×x

x = 4×8/3

x = 32/3 = 10 3/2

3.x:1000: :24:140

x/1000= 24/140

x/1000 = 6/ 35

x ×35 = 6×1000

x = 6×1000/35

x = 1200/7