Question

Given that `log_2 3 = a, log_3 5=b,log_7 2=c`,then the value of `log_(140) 63` is equal to
A. `(2+ac)/(2c+1+abc)`
B. `(1+2ac)/(c+2+abc)`
C. `(1+2ac)/(2c+1+abc)`
D. `(2+ac)/(c+2+abc)`

Answer 1

Correct Answer - C
`log_(140)63=(log_(7)7+2log_(7)3)/(2log_(7)2+log_(7)7+log_(7)5)`
`=(1+2ac)/(2c+1+abc)`