LOGARITHMS 15

Evaluate Log100 +  log 0.001 - log 0.0001+ log 0.00001

Solution

= Log100 + log 0.001 -  log 0.0001+ log 0.00001

= Log10² +  log 10^-3 – log 10^-4 + log 10^-5

= 2Log10 + (-3 log 10) – (-4log 10) + (-5log 10)

= (2x1) + (-3x1) - (-8x1) + (-5 x 1)

= 2 + (-3) – (-4) -5

= 2 - 3 + 4 - 5

= 2 + 4 - 3 - 5

= 6 - 8

= 2  

Hence Log100 + log 0.001-  log 0.0001+ log 0.00001 = 2

TRY THIS……………………… 

Evaluate Log100 +  log 100,000 - log 0.0001+ log 0.00001