Answer :
To express the number [tex]$145\,000$[/tex] in scientific notation, we need to write it in the form
[tex]$$
a \times 10^b,
$$[/tex]
where [tex]$1 \leq a < 10$[/tex] and [tex]$b$[/tex] is an integer.
Step 1: Write out the number without commas:
[tex]$$
145{,}000 = 145000
$$[/tex]
Step 2: Move the decimal point so that it is immediately to the right of the first nonzero digit. In the number [tex]$145000$[/tex], placing the decimal after the first digit gives:
[tex]$$
1.45
$$[/tex]
Step 3: Count the number of places you moved the decimal point. The decimal was originally at the end of [tex]$145000$[/tex] (which can be thought of as [tex]$145000.0$[/tex]) and was moved 5 places to the left:
[tex]$$
145000 = 1.45 \times 10^5.
$$[/tex]
Thus, the number [tex]$145\,000$[/tex] expressed in scientific notation is:
[tex]$$
1.45 \times 10^5.
$$[/tex]
Therefore, the correct choice is option E.
[tex]$$
a \times 10^b,
$$[/tex]
where [tex]$1 \leq a < 10$[/tex] and [tex]$b$[/tex] is an integer.
Step 1: Write out the number without commas:
[tex]$$
145{,}000 = 145000
$$[/tex]
Step 2: Move the decimal point so that it is immediately to the right of the first nonzero digit. In the number [tex]$145000$[/tex], placing the decimal after the first digit gives:
[tex]$$
1.45
$$[/tex]
Step 3: Count the number of places you moved the decimal point. The decimal was originally at the end of [tex]$145000$[/tex] (which can be thought of as [tex]$145000.0$[/tex]) and was moved 5 places to the left:
[tex]$$
145000 = 1.45 \times 10^5.
$$[/tex]
Thus, the number [tex]$145\,000$[/tex] expressed in scientific notation is:
[tex]$$
1.45 \times 10^5.
$$[/tex]
Therefore, the correct choice is option E.
