A) To know how many times greater 9*10⁵ is from 3*10³, you have to divide both values:
[tex]\frac{9\cdot10^5}{3\cdot10^3}[/tex]You can divide this fraction into two:
[tex]\frac{9}{3}\cdot\frac{10^5}{10^3}[/tex]And solve them separatelly, afterwards you can multiply the results of both fractions:
[tex]\frac{9}{3}=3[/tex][tex]\frac{10^5}{10^3}=10^{5-3}=10^2[/tex]Note: when you divide two exponents values with the same base number, you have to subtract both exponent numbers.
Multiply both results:
[tex]3\cdot10^2=300[/tex]9*10⁵ is A. 300 times larger as 3*10³
B) To calculate how many times 5*10⁻³ is smaller than 5*10⁻², you have to divide the greater number by the smaller number.
[tex]\frac{5\cdot10^{-2}}{5\cdot10^{-3}}[/tex]Following the same procedure as before:
[tex]\frac{5}{5}\cdot\frac{10^{-2}}{10^{-3}}[/tex][tex]\frac{5}{5}=1[/tex][tex]\frac{10^{-2}}{10^{-3}}=10^{-2-(-3)}=10^{-2+3}=10^1[/tex]Reunite both values:
[tex]1\cdot10^1=10[/tex]5*10⁻³ is B. 10 times smaller as 5*10⁻²