Q:

A spring stretches in relation to the weight hanging from it according to the weight hanging from it according to the equation y = 0.75x + 0.25 where x is the weight in pounds and y is the length of the spring in inches. How to graph the equation including axis labels How to interpret the slope and the y-intercept of the line

Accepted Solution

A:
Draw a set of coordinate axes.  Label the horiz. axis "x" (to represent weight) and label the vert. axis "y" (to represent length of the spring).

y= spring length = 0.75x + 0.25 (measured in inches).
First, let x=0.  y will then be 0.75(0) + 0.25.  This is your "vertical intercept."
Now position your pencil on that point (0,0.25).   Move your pencil point 1.00 unit to the right from (0,0.25) and then up 0.75 unit.  This is what the "slope" means:  rise over run.  Here the rise is 0.75 and the run is 1.00.

The slope, 0.75, tells us by how much more the spring stretches as 1 more lb of weight is added to the weight already hanging from the spring.