Respuesta :

5/11 and 6/12

  • Cross multiply.
  • 5 * 12 = 11 * 6
  • 60 = 66
  • This is UNTRUE, so this does not form a proportion.

7/13 and 21/39

  • Cross multiply.
  • 7 * 39 = 13 * 21
  • 273 = 273
  • This is TRUE, so this forms a proportion. Let's keep going to make sure that this is our answer.

8/14 and 24/30

  • Cross multiply.
  • 8 * 30 = 14 * 24
  • 240 = 336
  • This is UNTRUE, so this does not form a proportion.

10/20 and 20/30

  • Cross multiply.
  • 10 * 30 = 20 * 20
  • 300 = 400
  • This is UNTRUE, so this does not form a proportion.

Your answer is 7 : 13 and 21 : 39 are a pair of ratios that form a proportion.

Answer:

7/13 and 21/39

   Cross multiply.

   7 * 39 = 13 * 21

   273 = 273

   This is TRUE, so this forms a proportion.

Step-by-step explanation: