Question #0c8b4

1 Answer
Dec 8, 2014

The application of the properties of logarithms is needed here to solve for the value of x.

log a - log b = log (a/b)
This is a common logarithm. Therefore, the base is 10

Applying this property,

log 3(x) - log 3(x+6) = -1

log[ (3x)/(3(x+6)]] = -1

then applying log b = y, which is 10^y = b

Therefore,

[(3x)/(3(x+6))] = 10^-1

take note, a^-1= (1/a)

Simplifying,
(3x)/(3x+18) = 1/10

then we cross multiply

10*3x = 1* (3x+18)
30x = 3x +18

add -3x to both sides

30x -3x = 3x +( -3x) +18

then,

27x = 18

divide by 27

x= (18/27)

reducing to lowest term

x= 2/3

we are asked to round off to two decimals. Therefore the answer is 0.67