Final answer:
The slope-intercept equation for a line with a slope of -3 and a y-intercept of (0,9) is y = -3x + 9.
Step-by-step explanation:
The slope-intercept equation for a line with a slope of -3 and a y-intercept of (0,9) is y = -3x + 9.
In this equation, the slope -3 represents the rate of change of y with respect to x, which means that for every increase of 1 unit in x, y decreases by 3 units. The y-intercept (0,9) is the point where the line intersects the y-axis with a value of 9.
The equation y = -3x + 9 represents a line that has a negative slope, meaning it slopes downwards from left to right, and intersects the y-axis at the point (0,9).