Question

What is the solution to the equation log base(2) x – log base(2) 4 = 2?

a. x = 1
b. x = 18
c. x = 8
d. x = 16

Answer 1

log2 x - log2 4 = 2
log 2 x = log2 4 +2
\[\log_{a} x = \log_{b} x/\log_{c} a\]
this way, log2 4 = log 4 / log 2 (log10 2) = 2
log2 x = 4
2^4 = x
x = 16