LOGARITHMS 4

Log₄7x – Log₄(x+3)-Log₄5=0.

Solution

Log₄7x – [ Log₄(x+3) + Log₄5]=0.

Log₄{7x/(x+3)5} =0.

7x      =   4⁰   = 1

x+3

7x    = 1

x+3

x + 3 = 7x

 3 = 7x - x

3 = 6x

¹3 = 6x

₂6   6 

½ = x 

Hence x=½

TRY THIS……………………….. 

NECTA 2011,  QN 2a

Log₄5x – Log₄(x+2) - Log₄3 = 0.