Help me evaluate this equation in Scientific Notation How do i solve this using Scientific Notation? 
$$ \frac{3\times 10^8}{4\times 10^{-5}} $$
I have been trying for hours now! Help please

First note that 
$$ \frac{x^a}{x^{-b}}= \frac{x^a}{\frac{1}{x^{b}}}=x^ax^b =x^{a+b}, \quad x\not =0$$
So now
$$ \frac{3\times 10^8}{4\times 10^{-5}}= \frac{3}{4}\times \frac{10^8}{10^{-5}}= \frac{3}{4}\times 10^8\times 10^5 $$
$$= 0.75\times 10^{8+5}= 0.75\times 10^{13}=7.5\times 10^{12}$$
