Answer:
4
Step-by-step explanation:
In place value, you would move the decimal point 4 places. You move it 4 places because 10,000 has 4 zeroes.
Depending on how flexibly you interpret "about 20 times larger" to mean, the answers are B and D.
Check the ratios of the larger number to the smaller number:
A: (2.01 x 10^7)/(4.25 x 10^6) = 2.01/4.25 x 10^1 = 20.1/4.25 = 4.729
B: (8.21 x 10^-3)/(4.13 x 10^-4) = 8.21/4.13 x 10^1 = 82.1/4.13 = 19.879
C: (4.91 x 10^6)/(5.09 x 10^3) = 4.91/5.09 x 10^3 = 4910/5.09 = 964.637
D: (5.97 x 10^4)/(3.12 x 10^3) = 5.97/3.12 x 10^1 = 59.7/3.12 = 19.135
1+3+5+7+103=119. I hope this is what you were asking for! :)
Answer: 
Step-by-step explanation:
Any negative exponent can be moved to the other side of the fraction as a positive exponent.
Thus, simply move the negative exponents to get: 5a^2/b*b^8*-10a^4. Then, use the exponent rule to get 5a^2/-10a^4b^9
Hope it helps <3