Log (40^2-20^2) is equal to

• Logarithms

Log (40² - 20²) is equal to

1. log 3
2. log 60 + log 20
3. log 40 – log 20
4. log 20

Solution

(a² - b²) = (a-b)(a+b)

(40² - 20²) = (40-20)(40+20) = 20*60

Now using product property of log

Log (a*b) = Log a + Log b 

Log (20*60) = Log 20 + Log 60

Correct option is B.