Question

write in scientific notation and std form
(5 x 10^2) (7 x 10^-4)

Answer 1

Std = 0.35
SN = 3.5x10^-1

Answer 2

How did you get to the -1 exponent? That is where I got lost

Answer 3

\[5\times 7=35\]
\[10^{2}\times 10^{-4}=10^{-2}\]so you have
\[35\times 10^{-2}\]
but this is not scientific notation, because 35 is larger than ten

Answer 4

so you have to change 35 to 3.5

Answer 5

since you moved decimal one place to the left, you have to compensate in the exponent.
\[35\times 10^{-2}=35\times 0.01=0.35\] to put this number in scientific notation you need
\[3.5\] so you write
\[3.5\times 10^{-1}\] which is
\[3.5\times 0.1=0.35\]