What is the equation of this line in slope-intercept form? y=3x−1

y=−3x−1

y = 3x + 1

y=−13x−1
Number graph ranging from negative six to six on the x and y axes. A line is drawn on the graph that passes through the labeled points begin ordered pair negative 1 comma 2 end ordered pair and begin ordered pair 1 comma negative 4 end ordered pair

9514 1404 393

  y = −3x −1

Step-by-step explanation:

The slope of the line between the two given points (-1, 2) and (1, -4) can be found using the slope formula:

  m = (y2 -y1)/(x2 -x1)

  m = (-4 -2)/(1 -(-1)) = -6/2 = -3

The slope is the coefficient of x in the slope-intercept equation for a line. Only one answer choice shows a slope of -3:

  y = -3x -1

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Additional comment

If you plot the given points and draw a line through them, you see that the y-intercept is -1. Or, you can use this equation to find the y-intercept from one of the points.

  b = y - mx

  b = 2 -(-3)(-1) = 2 -3 = -1

Now you know m=-3 and b=-1, so you can fill in the slope-intercept form equation:

  y = mx +b

  y = -3x -1

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