Proportions Math Example 1

Follow the full solution, then compare it with the other examples linked below.

Example 1

easy
Solve the proportion x6=1015\frac{x}{6} = \frac{10}{15}.

Solution

  1. 1
    Cross-multiply: 15x=6×10=6015x = 6 \times 10 = 60.
  2. 2
    Divide both sides by 15: x=6015=4x = \frac{60}{15} = 4.
  3. 3
    Check: 46=23\frac{4}{6} = \frac{2}{3} and 1015=23\frac{10}{15} = \frac{2}{3} \checkmark

Answer

x=4x = 4
A proportion states that two ratios are equal. Cross-multiplying converts the proportion into a simple linear equation that you can solve for the unknown.

About Proportions

An equation stating that two ratios are equal, used to find an unknown when three of the four values are known.

Learn more about Proportions →

More Proportions Examples

Example 2 medium

If 5 notebooks cost [formula]8.75$, how much do 12 notebooks cost?

Example 3 easy

Solve: [formula].

Example 4 hard

A car travels 180 km on 15 litres of fuel. How many litres are needed for a 540 km trip?

Example 5 medium

Solve the proportion: [formula].

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