Showing this number is irrational

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Prove the number $\log_2 3$ is irrational

My attempt:

Assume that $\log_2 3 $ is rational

By definition $\log_2 3 =y$

Also by definition $y=\frac{a}{b}$ such that $b \neq 0$

Now you have $ 2^{\frac{a}{b}}=3$

Thus raising both sides by $b$ you arrive at $2^{a}=3^{b}$

Therefore $b=a\frac{\log2}{\log3}$ and $a=b\frac{\log3}{\log2}$

Now I'm not sure what to do with this at this point. Any hints or mistakes I'm making will be helpful this is a new technique for me.

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Since $2^a = 3^b$, $3^b$ is an even number unless $a = 0$. If $a = 0$, $3^b = 1$. This is impossible since $b\neq 0$.