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Instructor Overview

In this lesson, students write formulas to represent different rate relationships.

Key Concepts

A formula is a mathematical way of writing a rule for computing a value.

Formulas, like c = 2.50w or d = 20g, describe the relationship between quantities.

  • The formula c = 2.50w describes the relationship between a cost and a quantity that costs $2.50 per unit of weight. Here, w stands for any weight, and c stands for the cost of w pounds at $2.50 per pound.
  • The formula d = 20g describes the relationship between the distance, d, and the number of gallons of gas, g, for a car that gets 20 miles per gallon.

Goals and Learning Objectives

  • Use equations with two variables to express relationships between quantities that vary together.