How did he get from 3^-16/3/3^-8/3 to 0.00285333857/0.00285333857??? (The circled part) Because when I put it in the calculator I don’t get the decimal I was suppose to get.

Step-by-step explanation:
[tex] \frac{ {3}^{ - \frac{16}{ 3} } }{ {3}^{ - \frac{ 8}{3} } } = \frac{0.002853338}{0.05341665075} [/tex]
I think, he made a mistake because the exponents have different values but then if you'll look at his results, he just wrote the same thing. If you want, you could post the original problem, and I'll solve it for you :)