Answer:
8.7 \times 10^{-5}
Step-by-step explanation:
Given that the diameter of a human hair
Given that the diameter of a spider's silk
Now we have to find how much greater is the diameter of a human hair than the diameter of a spider's silk. To find that we just need to subtract the given numbers. Since powers are not same so let's make them equal now we can easily subtract the coefficients that is 3 from 9 = (90-3) \times 10^{-6}
= 87 \times 10^{-6}
= 8.7 \times 10^{-5}