chris2305
3

# Which of the following expressions is written in scientific notation? a)73.4*10^5 b)0.09*10^7 c)80*10^3 d)4.22*10^(–3) what is exactly scientific notation?

$a\cdot10^n\ is\ scientific\ notation\ if\ a\in\left<1;\ 10\right)\\\\a)\ 73.4\cdot10^5-NO-(73.4 > 10)\\\\b)\ 0.09\cdot10^7-NO-(0.09<1)\\\\c)\ 80\cdot10^3-NO-(80>10)\\\\d)\ 4.22\cdot10^{-3}-YES$