Question

determine whether each x-value is a solution (or an approximate solution) of the equation. 

log4(3x)=3
a. x≈21.333
b. x=-4
c. x=64/3

Answer 1

log4(3x) = 3
is the same as:

4³ = 3x
64 = 3x
64 / 3 = 3x / x
x = 64 / 3

x ≈ 21.333

Therefore, c is an exact solution, and a is an approximate solution (not showing all the repeating digits, so it's not exact).
Hope this helps! :)