Answer:
Step-by-step explanation:
If you want to find out how many times larger something is than something else, you have to divide. We will set up a problem that looks like this:
[tex]\frac{2.1*10^8}{4.2*10^2}[/tex]
Diving 2.1 by 4.2 gives us .5; to divide the exponents, we remember that if we divide like bases we have to subtract the exponents. 10 is our base in both cases, so 8 - 2 gives us 6, resulting in:
[tex].5*10^6[/tex]
However, this isn't in scientific notation. We need to move the decimal one more place to the right, which in trn reduces the exponent by 1:
[tex]5*10^5[/tex]