How do you solve Log_[2]x + log_[2]x + 1= 2 - log_[2] (1/3)?

1 Answer
Dec 7, 2015

x= sqrt 6

Explanation:

Given log_2x + log_2x+ 1= 2-log_2(1/3)

Step 1: Manipulate the equation to have all logarithm on one side, like so

log_2x + log_2x +log_2(1/3) = 2-1

Step 2: Use the sum to product logarithmic properties
logAB= log A + log B

log_2x + log_2x +log_2(1/3) = 1
log_2(x*x*1/3)=1
log_2 (1/3 x^2) = 1
Change logarithmic equation to exponential form since
log_ax = y hArr a^y = x
2^1 = 1/3 x^2
6= x^2
x= +-sqrt6

Only positive answer would work because the domain logx exist if x>0