We have
-2x-3y <12
For this case what you should do is to graph the following straight line:
-2x-3y = 12
Then, the solution will be the shaded region that satisfies the following inequality:
-2x-3y <12
In the shaded region you will find all the solution points.
Answer:
See attached image
If he types 40 words a minute, he can type 2000 words in 50 minutes you can solve this by doing 40*50 the number of hours would be less than one
16 it is as easy as multiplying
Given equation is y=2x+7 and 
Let's simplify the 2nd equation
before we can start graph so that calculation will be easy

multiply both sides by 2 to cancel out fractions

y=2x+7
which is exactly same as the first equatoin so graph of both will be exactly same and solution will be infinitely many solutions.
y=2x+7 has y-intercept 7 so first point will be (0,7). Slope is 2 so rise 2 unit up then 1 right and graph the new point.
The class midpoint is the lower class limit plus the upper class limit divided by 2 . Add the midpoints column to the original table.