Describe a real-world situation where the relationship is linear and nonproportional.

A 10-inch candle burns at a constant rate of 1 inch per hour.

Rule in words: To determine the height of the candle multiply the number of hours that the candle burns by 1 inch per hour, and subtract the product from the candle’s initial height (10 inches).

Rule in Equation: If y represents the height of the candle after x hours of burning, then the relationship can be expressed as an equation in the form y = mx + b, where m represents the rate at which the candle burns (1 inch per hour) and b represents the initial height of the candle (10 inches).

Height of Candle = Rate at which it Burns • Number of Hours Burned + Initial Height

y = - 1 • x + 10, or y = 10 - 1x