Multiple choice

For $x, a>0$ the root(s) of the equation ${\log}{ax}a+{\log}{ax}{a}^{2}+{\log}_{{a}^{2}x}{a}^{3}=0$ is (are) given by

  1. ${a}^{\cfrac{-4}{3}}$
  2. ${a}^{\cfrac{-3}{2}}$
  3. ${a}^{-1}$
  4. ${a}^{-2}$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Using log base change rules, the equation becomes 1/(1+log_a(x)) + 2/(1+log_a(x)) + 3/(2+log_a(x)) = 0. Let y = log_a(x), then 3/(1+y) + 3/(2+y) = 0, leading to y = -1.5, so x = a^(-1.5).

AI explanation

Using the change of base formula, rewrite the logarithms as $1/(1 + \log_a x) + 2/(1 + \log_a x) + 3/(2 + \log_a x) = 0$. Let $y = \log_a x$, turning the equation into $3/(1 + y) + 3/(2 + y) = 0$, which simplifies to $3(3 + 2y) = 0$ and yields $y = -3/2$. Since $y = \log_a x = -3/2$, converting this back to exponential form gives the root as $x = a^{-3/2}$.