To LJ: Graph Shading

Before you start, blogger don't allow the use of triangle brackets, which is our 'less than' and 'more than' sign because they are for html, so i use all words. Might be hard to read.

Let's say one equation is
y more than x+1
Before u shade, you need to sketch the graph of y=x+1 (notice the '=' and 'less than' sign in the equations).
Then you shade the region that is ABOVE the graph, because Y is GREATER than x + 1. (y is larger when the points move upwards towards y axis, thats y if GREATER then shade region ABOVE)

if equation is y less than x+1, then you reverse the process. on your y-axis, the lower you go, the smaller the number. so if y is LESS THAN, then shade BELOW

Similarly, you can also look the graph in terms of x. look at y bigger than x+1, if you reverse the equation, you can see
1+x less than y
If x is the subject of concern, then look at x-axis. The numbers are SMALLER on the LEFT side, so if 1+x is SMALLER, then shade LEFT. Same applies to the equation if 1+x more than y. If 1+x is BIGGER, then shade on the RIGHT hand side of the graph.

You can actually combine and look at both x and y at the same time. Lets say 1+x less than y, if you look at x, x is SMALLER. then you look at y. Y is on the BIGGER side. So if X SMALLER Y BIGGER, you need to shade LEFT AND UP of the graph. (They can never go wrong. You won't have a condition where X and Y are not synchronized, like for the example just now, you won't find that you can shade up but you cannot shade left punya case)

A VERY IMPORTANT NOTE!
If coefficient of x or y is NEGATIVE, you need to shade in the terbalik way. EG:
1-x less than y. If x is LESS, y is MORE, you should shade LEFT (X small), and UP (y big). But if you plot the downwards slopping equation 1-x=y (gradient is negative), you can NEVER EVER shade the region of left and up together.

Reason?
Because coefficient of x is negative.
(Try plotting the graph if dun understand then you know why)

If you make x positive, you will get an equation of 1 less than y+x. so now BOTH X AND Y are on the BIGGER side, you will need to shade RIGHT and UP of the graph, which is correct.