Question

Use the properties of exponents to simplify the following expression. Write the answer in scientific notation.
(5.6x10^5) (9.9x10^-8) divided by
(8.4x10^-4) (5x10^6)

=28.9x10^-1
I added 5.6 9.9 8.4 5
5+-8+-4+6+ -1

Answer 1

Oh my!!!
you are dealing with a multiplication and division of numbers, why are you adding them ?

your question:

(5.6x10^5) (9.9x10^-8) /( (8.4x10^-4) (5x10^6) )
= (5.6)(9.9)(10^-3) / ((8.4)(5)(10^2) )
= 55.44x10^-3 /(42 x 10^2)
= 1.32 x 10^-5

look at my solution line by line, and study what I did
remember that when dividing powers of the same base, we keep the base and subtract the exponents

so 10^-3 ÷ 10^2
= 10^(-3-2)
= 10^-5