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Solving Proportions

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  • Portion: An equality of two ratios

Find two equivalent ratios for each
[3/5]

  • [(3 ×2)/(5 ×2)] = [6/10]
  • [(6 ×2)/(10 ×2)] = [12/20]

[6/10],[12/20]

Find two equivalent ratios for each
[11/44]

  • [(11 ÷11)/(44 ÷11)] = [1/4]
  • [(1 ×2)/(4 ×2)] = [2/8]

[1/4],[2/8]

Use mental math to solve the proportion
[3/5] = [x/10]

  • [(3 ·2)/(5 ·2)] = [x/10]

x = 6

Use mental math to solve the proportion
[1/8] = [x/24]

  • [(1 ·3)/(8 ·3)] = [x/24]

x = 3

Use mental math to solve the proportion
[3/z] = [12/16]

  • [(3 ·4)/(z ·4)] = [12/16]

z = 4

Tell whether the two ratios form a proportion
[4/40],[8/80]

  • [(4 ×2)/(40 ×2)] = [8/40]

Yes

Tell whether the two ratios form a proportion
[12/24],[24/47]

  • [(12 ×2)/(24 ×2)] = [24/48]

No

Tell whether the two ratios form a proportion
[13/26],[25/52]

  • [(13 ×2)/(26 ×2)] = [26/52]
  • [26/52] ≠ [25/52]

No

Solve the proportion
[5/x] = [2/20]

  • 2x = 5 ·20
  • 2x = 100
  • [2x/2] = [100/2]
  • x = [100/2]

x = 50

Solve the proportion
[2/4] = [y/16]

  • 4y = 2 ·16
  • 4y = 32
  • [4y/4] = [32/4]
  • y = [32/4]

y = 8

*These practice questions are only helpful when you work on them offline on a piece of paper and then use the solution steps function to check your answer.

Answer

Solving Proportions

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Mathematics: Basic Math