Deirdre,
Aline with a negative slope means that for every positive increment in x there will be a negative increment in y.For example a line with a slope of say -3 will have an equation y=-3x so for x=1 y=-3 and for x=2 y=-6. so you can see that for every positive increment in x i.e. x=1 to x=2 that y goes from -3 to -6 a change of -3.
Now if we add a negative intercept say -5 then our example line becomes y=-3x-5. This means y=-5 qt x=0. Once you know the slope and the intercept you can draw the complete line.
Hope this helps
Jim
