help i need an answer !

The answer to #1 is 0.
In order to find the answer to this one (or any of these problems, simply follow the order of operations. In the case of #1, we first want to stick the 0 in for a and then continue.
[tex] \frac{a}{b} +\frac{a + 1}{b} +\frac{a - 1}{b} [/tex]
[tex] \frac{0}{b} +\frac{0 + 1}{b} +\frac{0 - 1}{b} [/tex]
[tex] \frac{1}{b} +\frac{-1}{b} [/tex]
Since these two numbers cancel, you will get the answer as 0. For the rest of these, follow the basic steps provided by your teacher in PEMDAS.