Section 1
Writing an Equation from a Word Problem
Property
To translate a real-world word problem into a two-variable equation, follow these steps:
- Identify the two changing quantities: Determine what the independent variable (input) and dependent variable (output) are.
- Define Variables: Choose letters to represent these two unknown quantities.
- Find the Rule: Identify the mathematical operation (addition, subtraction, multiplication, or division) that connects the two variables.
- Write the Equation: Assemble the variables and the rule into an equation showing how the output relates to the input.
Examples
- Problem: A streaming service charges 8 dollars per month. What is the total cost for a certain number of months?
- Variables: Let m represent the number of months (independent) and C represent the total cost (dependent).
- Equation: C = 8m
- Problem: A plant is currently 5 inches tall and grows 2 inches every week.
- Variables: Let w represent the number of weeks (independent) and h represent the total height (dependent).
- Equation: h = 5 + 2w