what is the answer to 1/7=x/28

Question

I was sick from school today, so I didn't know how to solve 12 questions. I will show you the questions.

1. 1/7=x/28

2. 2/3=x/20

3. 2/7=x/21

4. 6/7=x/35

5. 1/10=x/30

6. 6/7=x/14

7. 3/8=9/x

8. 1/3=14/x

9. 45=20/x

10. 2/x=14/21

11. 8/x=16/18

12. 1/x=4/36

 

Answer 1

1. 1/7=x/28, x=28/7=4

2. 2/3=x/20, x=20×⅔=40/3

3. 2/7=x/21, x=21×2/7=3×2=6

4. 6/7=x/35, x=35×6/7=5×6=30

5. 1/10=x/30, x=30/10=3

6. 6/7=x/14, x=14×6/7=2×6=12

7. 3/8=9/x, x/9=8/3, x=9×8/3=3×8=24

8. 1/3=14/x, x/14=3, x=14/3

9. 45=20/x, x/20=1/45, x=20/45=(4×5)/(9×5)=(4/9)(5/5)=4/9

10. 2/x=14/21, x/2=21/14, x=2×21/14=2×(3×7)/(2×7)=3×7/7=3

11. 8/x=16/18, 8/x=8/9, x/8=9/8, x=9

12. 1/x=4/36, x=36/4=9