Answer:
To simplify the expression, we first need to perform the division before the addition.
6 x 10^-2 / (7 x 10^4) = 6/7 x 10^-2-4 = 0.000085714.... ≈ 8.57 x 10^-5
Now the expression becomes:
3 x 10^-3 + 8.57 x 10^-5
To add these two terms, we need to have them in the same power of 10. Therefore, we can rewrite 3 x 10^-3 as 0.003 x 10^-3.
0.003 x 10^-3 + 8.57 x 10^-5 = 0.0030857 x 10^-3
Now we can express the answer in scientific notation by moving the decimal point to the left until we have a number between 1 and 10, and taking note of how many places we moved the decimal point.
0.0030857 x 10^-3 = 3.0857 x 10^-6
Therefore, the simplified form of 3 x 10^-3 + 6 x 10^-2 / (7 x 10^4) (3 x 10^8) expressed in scientific notation is 3.0857 x 10^-6.
This means that the answer is a very small number, which makes sense given the small values of the original terms.