Question

The water level of a river is 170 feet. The river recedes 4 feet each year. Ingrid claims that the equation that represents this scenario is y = 170x – 4. Is her equation correct? Explain.

Answer 1

Ingrid's equation is incorrect; it should be y = 170 - 4x, with a starting water level of 170 feet (the y-intercept) and a slope of -4, indicating the river recedes by 4 feet each year.

Step-by-step explanation:

Ingrid's equation y = 170x – 4 is not correct to represent the scenario of the river receding 4 feet each year. The correct linear equation would be y = 170 - 4x, where y represents the water level of the river after x years. The initial water level is 170 feet, so the y-intercept is 170. Since the river recedes 4 feet each year, the slope of the equation should be -4, reflecting a decrease in the water level over time.