Which equation represents a line with slope 3 and y-intercept -2?

Which equation represents a line with slope 3 and y-intercept -2?

• A. y = 3x - 2
• B. y = -3x + 2
• C. y = x - 2
• D. y = 3x + 2

Answer: (A)

This uses slope-intercept form, where y = mx + b, with m as the slope and b as the y-intercept. A line with slope 3 means the rise over run is 3 for every 1 unit the x changes, and a y-intercept of -2 means the line crosses the y-axis at -2 (the value of y when x is 0). Putting those together gives y = 3x + (-2), which is y = 3x - 2. That is the only option that has both a slope of 3 and a y-intercept of -2. The other options either have the wrong slope (negative 3, or 1) or the wrong intercept (positive 2).

This uses slope-intercept form, where y = mx + b, with m as the slope and b as the y-intercept. A line with slope 3 means the rise over run is 3 for every 1 unit the x changes, and a y-intercept of -2 means the line crosses the y-axis at -2 (the value of y when x is 0). Putting those together gives y = 3x + (-2), which is y = 3x - 2.

That is the only option that has both a slope of 3 and a y-intercept of -2. The other options either have the wrong slope (negative 3, or 1) or the wrong intercept (positive 2).