Answer:
A) 6.6248 x 10^-3
Explanation:
You first do the exponents of the 10s
(7.28 x 10^-2) = (7.28 x 0.01) , (9.1 x 10^-3) = (9.1 x 0.01)
Then multiply the parentheses
(7.28 x 0.01) = 0.0728 , (9.1 x 0.01) = 0.091
Then multiply both products together
0.0728 x 0.091
= 0.0066248
In order to simplify this into an equation you can count the amount of decimal placements you would need to move make a whole number, then the amount of placements is your exponent, in this case it is 3. Then since they're all 0s you use the base of 10 and since the value is shrinking you sue a negative exponent
0.006248-----> 6.6248 x 106-3