
Equivalence Relations
I am having trouble starting off with the two following problems.
 Let a R b on Q^+ if and only if a = b^k for some k is an element of Q
 Let a ~b on Z if and only if 7 divides (ab)
Can somebody show me how to prove the reflexive property for each. I can prove symmetric and transitive if I see how to approach each problem. Thanks

Both are so simple.
$\displaystyle \begin{gathered}
1 \in \mathbb{Q}^ + \;\& \;\left( {\forall x} \right)\left[ {x^1 = x^1 } \right] \hfill \\
x  x = 0\;\& \;70 \hfill \\
\end{gathered} $
