Exponents and Powers

If $$3^a + 3^b=756,  7^a + 2^c=375, 5^a + 3=128$$, then the value of $$a+b+c$$ is   
Simplify and express each of the following in exponential form:$$25^{ 4 }\div { 5 }^{ 3 }$$
Write the number of power of $$5$$.
Find
$$\sqrt[3]{{ - 125}} \times \sqrt[3]{{ 3375}}  $$
Numbers can be classified into two categories depending on their divisible conditions.
They are (i) Even numbers $$(2p) \  \forall p \epsilon N$$ (ii) odd numbers $$(2p + 1)  \ \forall p \epsilon N$$