Here's a couple more examples:
+5x: No reversing/reversing/"oppositing"
-7y: Positive slope
<: shade to the left of the line
-4: X-intercept is negative (to the left of the origin)
-3x: Everything will be reversed!
-6y: Positive slope, but since there's a -3x, it will be negative
<: Supposed to mean shade to the left, but it's right this time because of the -3x
-9: Like the others, generally means negative x-intercept. It will be positive because of the -3x
haha .. Thats a pretty long approach man ..
1. 5x-7y<-4, use origin as reference and put x=y=0.. it comes 0<-4 which is not true hence shade the portion which does not contain origin .. why bother yourself with so many things :p
2. -3x-6y<-9 , origin as reference, 0<-4 .. not true .. shade the portion which doesnt contain origin ..
results are same as yours ..
Forget Kudos ... be an altruist