How do you write the answer in scientific notation given #(9.9times10^9)/(1.5times10^8)#?

Question

2090 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2017-03-21T11:28:59

#6.6xx10#

#color(blue)("Preamble")#
Example demonstrating a principle using 'easy' numbers

Suppose we had #5^3/5^2#

This is the same as:#" "(5xx5xx5)/(5xx5)#

Split this so that we have:#" "5xx5/5xx5/5#

But #5/5=1#

#5xx1xx1 = 5#

Another way of doing this is:#" "5^3/5^2 = 5^(3-2)=5^1=5#

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#color(blue)("Answering the question")#

Write as:#" "9.9/1.5xx10^9/10^8#

Using the method as in the example write as:

#9.9/1.5xx10^(9-8)#

#9.9/1.5xx10^1#

but 9.9-:1.5=6.6# giving:

#6.6xx10#

We have a whole number to the left of the equals that is less than 10 so this is the finished answer.