Step-by-step explanation:
[tex]a^{-n}=\dfrac{1}{a^n}\\\\\text{therefore}\ 10^{-5}=\dfrac{1}{10^5}=\dfrac{1}{100000}=0.00001\\\\1.23\cdot10^{-5}=1.23\cdot0.00001=0.0000123[/tex]
[tex]a\cdot10^{-n}[/tex] - move the decimal point n place to the left
[tex]a\cdot10^n[/tex] - move the decimal point n place to the right
Examples:
[tex]1.2\cdot10^5=1\underbrace{20000}_{5\to}=120,000\\\\1.2\cdot10^{-5}=0\underbrace{.00001}_{\leftarrow5}2=0.000012[/tex]
