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Maths Exercices

Graph a line using the slope

If we know the coordinates of a point on a line, and if we know the slope of the line, we can use the slope to determine a second point on the line.

Graph the line with slope that passes through (-1,-3)

Strategy. First, we will plot the given point (-1,-3). Then we will use the slope to find a second point that the line passes through. Once we determine two points that the line passes through, we can draw the graph of the line.

Solution. To draw the graph, we begin by plotting the point (-1,-3). From there, we move 2 units up (rise) and the 5 units to the right (run), since the slope is 2/5. This locates a second point on the line, (4,-1). We then draw a straight line through the two points.

   
Plot the given point (-1,-3)
 

From (-1,-3) draw the rise and run parts of the slope triangle for m=2/5 to find another point on the line
 
Use a straightedge to draw a line through the points