Final answer:
The height of the candle after 3 hours is 12 inches.
Step-by-step explanation:
To write the equation in slope-intercept form, we need to determine the slope and y-intercept. The slope is the rate at which the candle burns, which is 1 inch per hour. The y-intercept is the initial height of the candle, which is 9 inches. Using the slope-intercept form, the equation is y = mx + b, where y is the height of the candle after x hours, m is the slope, and b is the y-intercept. Plugging in the values, we get y = 1x + 9. Simplifying the equation, we have y = x + 9.
To find the height of the candle after 3 hours, we substitute x = 3 into the equation. y = 3 + 9 = 12. So, the height of the candle after 3 hours is 12 inches.
Learn more about Equation in slope-intercept form