Select the ones that correctly demonstrate the operations of scientific notation

Note that more than one option may be correct. Select all the correct answers

A. (4.0 x 103) (5.0 x 105) = 2 x 10^9

B. 4.5x105/9.0x10° = 2 x 10^4

C. (2.1 x 105) + (2.7 x 105) = 4.8 x 10^5

D. (3.1 x 105) - (2.7 x 102) = 0.4 x 10^3

A and C

Step-by-step explanation:

A. /

(4.0 x 5.0) (10^3 x 10^5)

20 x 10^8

2.0 x 10^9

B. doesn't work, do not understand last number

C.

(2.1 + 2.7) (10^5 + 10^5) since powers are the same, do not need to change anything

4.8 x 10^5

D.

(3.1 - 2.7) (10^5 - 10^2) since powers are not the same, you need to make them equal

Do not need to subtract powers, hence D is untrue