Help guys please ....

Answer:
0.000008 m
Step-by-step explanation:
The diameter of a red blood cell is [tex]8\times 10^{-6}\ m[/tex]. We need to write the value in the standard notation.
[tex]10^{-6}[/tex] means there are 5 zeros before 8. It can be written as :
[tex]8\times 10^{-6}=\dfrac{8}{10^6}\ (\because x^{-a}=\dfrac{1}{x^a})\\\\=\dfrac{8}{1000000}\\\\=0.000008[/tex]
So, the standard notation is 0.000008 m. Hence, the correct option is (d).