How do you solve log_[4] (5x +1) - log_ [4] (x + 2) =1?
1 Answer
Apr 12, 2016
x = 7
Explanation:
Using the following
color(blue)" laws of logarithms "
• log x - logy = log(x/y)
• log_b a = n hArr a = b^n
log_4((5x+1)/(x+2)) = 1 rArr (5x+1)/(x+2) = 4^1 = 4 solve :
(5x+1)/(x+2) = 4 cross-multiply : 5x+1 = 4(x+2)
hence 5x + 1 = 4x+8
rArr x = 7