Are you saying that you do not know what "independent", "dependent", or "inconsistent" mean? I think you would be better served by looking up the definitions yourself in your text book.
There are a number of ways of determining whether or not a system of equations is "independent" or "consistent" but the simplest is to try to solve the equations and see what happens.
#3
Is this correct?
3x – 4y = 8
.75x - y = -2
so,
-4(0.75x – y) = (-2)-4
-3x + 4y = 8
0=16 This is inconsistent