Answer:
To graph a straight line:
find the y-intercept by taking x = 0
find the x-intercepts by taking y = 0
Draw a straight line joining these two points 
change in y depends on the slope. 
As x increases:
y increases if the slope is positive 
y decreases if the slope is negative 
As x decreases:
y increases if the slope is negative 
y decreases if the slope is positive