We know that,
color(red)((1)1/(a^n)=a^(-n)(1)1an=a−n
color(blue)((2)log_a x^n=nlog_a x(2)logaxn=nlogax
color(violet)((3)log_a a=1(3)logaa=1
Let
L=log_10(1/100)-log_10(1/1000)L=log10(1100)−log10(11000)
=log_10color(red)((1/(10^2)))-log_10 color(red)((1/(10^3))...toApply(1))
=log_10(10^color(blue)((-2)))-log_10(10^color(blue)((-3)))...tocolor(blue)(Apply(2))
=color(blue)(-2)log_10 10-color(blue)((-3))log_10 10
=-2color(violet)((1))+3(color(violet)(1))...tocolor(violet)(Apply(3)
=-2+3
=1