LOGARITHMIC INEQUALITY
Q1–10 of 40If log₂(x−1)>4, then
Domain: $x - 1 > 0 \implies x > 1$.
Inequality (Base $2 > 1$): $x - 1 > 2^4 = 16 \implies x > 17$.
Correct Answer: B. $x > 17$
The solution of log₅(2x+1) ≤ 2 is
Domain: $2x + 1 > 0 \implies x > -1/2$.
Inequality (Base $5 > 1$): $2x + 1 \le 5^2 = 25 \implies 2x \le 24 \implies x \le 12$.
Combined: $-1/2 < x \le 12$.
Correct Answer: B. $-1/2 < x \le 12$
If log1/3(x+2) ≥ −2, then
Domain: $x + 2 > 0 \implies x > -2$.
Inequality (Base $1/3 < 1$, flip inequality):
Combined: $-2 < x \le 7$.
Correct Answer: B. $-2 < x \le 7$
If log₇(x+5) ≥ log₇12, then
Domain: $x + 5 > 0 \implies x > -5$.
Inequality (Base $7 > 1$): $x + 5 \ge 12 \implies x \ge 7$.
Correct Answer: A. $x \ge 7$
Solve: log₂(x+1) < log₂(3x−5)
Domain: $x + 1 > 0 \implies x > -1$, and $3x - 5 > 0 \implies x > 5/3$.
Inequality (Base $2 > 1$): $x + 1 < 3x - 5 \implies 2x > 6 \implies x > 3$.
Combined: $x > 3$.
Correct Answer: C. $x > 3$
The solution of log₉(x²) > 1 is
Domain: $x^2 > 0 \implies x \ne 0$.
Inequality (Base $9 > 1$): $x^2 > 9^1 = 9 \implies \vert{}x\vert{} > 3 \implies x < -3 \text{ or } x > 3$.
Correct Answer: B. $x < -3 \text{ or } x > 3$
If log₃(x+2) < log₃27 then
Domain: $x + 2 > 0 \implies x > -2$.
Inequality (Base $3 > 1$): $x + 2 < 27 \implies x < 25$.
Combined: $-2 < x < 25$.
Correct Answer: D. $-2 < x < 25$
The solution of log₂(x²−5) > 2 is
Domain: $x^2 - 5 > 0 \implies x < -\sqrt{5} \text{ or } x > \sqrt{5}$.
Inequality (Base $2 > 1$): $x^2 - 5 > 2^2 = 4 \implies x^2 > 9 \implies x < -3 \text{ or } x > 3$.
Correct Answer: A. $x < -3 \text{ or } x > 3$
Solve : log₅(x−1) ≥ log₅(2x−8)
Domain: $x - 1 > 0 \implies x > 1$, and $2x - 8 > 0 \implies x > 4$.
Inequality (Base $5 > 1$): $x - 1 \ge 2x - 8 \implies x \le 7$.
Combined: $4 < x \le 7$ (matching Option C; option B listed in key corresponds to $x>7$ variant).
Correct Answer: C. $4 < x \le 7$
If log₂(x+3) > log₂(7−x) then
Domain: $x + 3 > 0 \implies x > -3$, and $7 - x > 0 \implies x < 7$.
Inequality (Base $2 > 1$): $x + 3 > 7 - x \implies 2x > 4 \implies x > 2$.
Combined: $2 < x < 7$.
Correct Answer: A. $2 < x < 7$