Express 8 x 10^6 ÷ 4 x 10^2 In Scientific Notation.?

It's similar to your multiplication one, but instead of adding the exponents, you subtract them, so:

(8 * 10^6) / (4 * 10^2)
2 * 10^4

While D is the same value, it isn't in scentific notation since it requires the non-10 portion to be greater than or equal to 1, and less then 10.

As a rule of thumb, 10^5 is just 100000, where the 5 is just how many zeros. For a negative number, 10^-5, you count the decimal places back from 1.0, so you get .00001, if you jump the decimal point 5 times, you get 1.0 back. Scientific notation always starts with the decimal point after the first number for example, 3.67, or 1.23. 123 is just 1.23 x 10^2, moving the decimal point 2 times to the right.

C. 2.0 x 10^4

If you follow the order of operations, you do the exponents first. Then multiply and divide from left to right.

You get 20000 which is C.

I assume you mean
(8*10^6)/(4*10*2) #divide numerator and denominator both by 4
(2*10^6)/(10^2) #divide numerator and denominator both by 100
2*10^4

you divide 8 by 4 which gives you the 2.0

then divide 10^6 by 10^2
to do this you subtract the exponents from eachother,
and you get 10^4

so C

C. 2.0 x 10^4
8000000/400 =
20000= 2.0000 x 10^4

(8 x 10^6)/(4 x 10^2)
= (8/4) x (10^6/10^2)
= 2 x [10^(6 - 2)]
= 2 x 10^4
(answer C)