Writing Equations from Context Math Example 2

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Example 2

medium
A plumber charges \50 for a visit plus \30 per hour. If the bill was \$170, how many hours did the job take?

Solution

  1. 1
    Let hh = hours. Total cost: 50+30h=17050 + 30h = 170.
  2. 2
    Subtract 50: 30h=12030h = 120.
  3. 3
    Divide by 30: h=4h = 4 hours.

Answer

h=4 hoursh = 4 \text{ hours}
Identify the fixed cost (\50 visit fee) and the variable cost (\30 per hour). The total equals the sum of both.

About Writing Equations from Context

Translating real-world situations and word problems into algebraic equations by identifying the unknown, choosing a variable, and expressing relationships mathematically.

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More Writing Equations from Context Examples

Example 1 easy

Write an equation: 'Three times a number decreased by 4 is 17.'

Example 3 easy

Write an equation: 'Half of a number plus 6 equals 10.'

Example 4 hard

The perimeter of a rectangle is 34 cm. The length is 5 cm more than the width. Find the dimensions.

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