Laws of Logarithms

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turkey-yks 2012 Q30 Solve a Logarithmic Equation
$$\log _ { 2 } 3x + \log _ { 4 } x ^ { 2 } = 2$$
What is the value of x that satisfies the equation?
A) $\frac { \sqrt { 2 } } { 2 }$
B) $\frac { 3 \sqrt { 2 } } { 2 }$
C) $\frac { 5 \sqrt { 2 } } { 2 }$
D) $\frac { \sqrt { 3 } } { 3 }$
E) $\frac { 2 \sqrt { 3 } } { 3 }$
turkey-yks 2013 Q6 Express One Logarithm in Terms of Another
For real numbers x and y
$$2 ^ { x } = 6 ^ { x + y - 1 }$$
Given this, what is $3 ^ { \mathbf { x } }$ in terms of y?
A) $3 ^ { 1 - y }$
B) $6 ^ { 1 - y }$
C) $6 ^ { y }$
D) $9 ^ { - y }$
E) $9 ^ { 1 + y }$
turkey-yks 2014 Q4 Solve a Logarithmic Equation
$\mathbf { x }$ is a real number and
$$\left( \frac { 1 } { 6 } \right) ^ { x } = \left( \frac { 4 } { 3 } \right) ^ { x + 1 }$$
Given this, what is $8 ^ { \mathbf { X } }$?
A) $\frac { 2 } { 3 }$
B) $\frac { 3 } { 4 }$
C) $\frac { 1 } { 8 }$
D) $\frac { 3 } { 8 }$
E) $\frac { 2 } { 9 }$
turkey-yks 2014 Q30 Solve a Logarithmic Equation
$$\log _ { 2 } \left( \frac { 1 } { \sqrt { x } } \right) + \log _ { 4 } \left( \frac { 4 } { y } \right) = 3$$
Given that, what is the product $x \cdot y$?
A) $\frac { 2 } { 3 }$
B) $\frac { 3 } { 4 }$
C) $\frac { 5 } { 6 }$
D) $\frac { 3 } { 8 }$
E) $\frac { 1 } { 16 }$
turkey-yks 2015 Q29 Solve a Logarithmic Equation
$\log _ { 4 } x$ and $\log _ { 4 } \left( x ^ { 2 } \right)$ are consecutive two positive even integers.
Accordingly, what is the value of $\log _ { x } 4$?
A) $\frac { 1 } { 2 }$
B) $\frac { 1 } { 4 }$
C) $\frac { 1 } { 16 }$
D) 1
E) 2
turkey-yks 2015 Q30 Solve a Logarithmic Equation
Let k be a positive real number such that for the function
$$f ( x ) = \log _ { x } ( x - k )$$
we have $f ( 3 k ) = \frac { 2 } { 3 }$. What is k?
A) $\frac { 3 } { 8 }$
B) $\frac { 9 } { 8 }$
C) $\frac { 27 } { 8 }$
D) $\frac { 2 } { 9 }$
E) $\frac { 4 } { 9 }$
turkey-yks 2016 Q30 Prove a Logarithmic Identity
Let t be a real number. The equalities
$$\begin{aligned} & x = e ^ { 2 \cos t } \\ & y = e ^ { 3 \sin t } \end{aligned}$$
are given.
Accordingly, which of the following gives the relationship between $x$ and y that is satisfied for every real number t?
A) $\ln ^ { 2 } x + \ln ^ { 2 } y = 4$
B) $\ln ^ { 2 } x + \ln ^ { 2 } y = 9$
C) $9 \ln ^ { 2 } x + 2 \ln ^ { 2 } y = 27$
D) $\ln ^ { 2 } x + 4 \ln ^ { 2 } y = 28$
E) $9 \ln ^ { 2 } x + 4 \ln ^ { 2 } y = 36$
turkey-yks 2016 Q31 Simplify or Evaluate a Logarithmic Expression
$$\log _ { 2 } \sqrt { 8 \sqrt { 4 \sqrt { 2 } } }$$
What is the result of this operation?
A) $\frac { 13 } { 8 }$
B) $\frac { 15 } { 8 }$
C) $\frac { 17 } { 8 }$
D) $\frac { 23 } { 16 }$
E) $\frac { 27 } { 16 }$
turkey-yks 2017 Q33 Simplify or Evaluate a Logarithmic Expression
$\frac { \log _ { 3 } \sqrt { 27 } + \log _ { 27 } \sqrt { 3 } } { \log _ { 3 } \sqrt { 27 } - \log _ { 27 } \sqrt { 3 } }$\ What is the result of this operation?\ A) $\frac { 3 } { 2 }$\ B) $\frac { 4 } { 3 }$\ C) $\frac { 5 } { 4 }$\ D) $\frac { 6 } { 5 }$\ E) $\frac { 7 } { 6 }$
turkey-yks 2017 Q34 Solve a Logarithmic Equation
$\ln x + \ln y = 9$ $$\ln x - \ln y = 3$$ Given this, what is the value of $\log _ { y } x$?\ A) 1\ B) 2\ C) 3\ D) 4\ E) 5
turkey-yks 2018 Q10 Simplify or Evaluate a Logarithmic Expression
On a ruler-like scale with integers from 1 to 50 written on it, the distance of each integer $n$ from 1 is $\log n$ units.
When two identical rulers with this property are placed one below the other as shown in the figure, the number 42 on the upper ruler aligns with the number 28 on the lower ruler, and the number 33 on the upper ruler aligns with the number $x$ on the lower ruler.
Accordingly, what is $x$?
A) 18 B) 19 C) 20 D) 21 E) 22
turkey-yks 2018 Q11 Solve a Logarithmic Equation
The arithmetic mean of $\log _ { 4 } \mathrm { x }$ and $\log _ { 8 } \frac { 1 } { \mathrm { x } }$ is $\frac { 1 } { 2 }$.
Accordingly, what is the value of $\log _ { 16 } \mathbf { x }$?
A) $\frac { 1 } { 2 }$ B) $\frac { 3 } { 2 }$ C) $\frac { 5 } { 2 }$ D) $\frac { 1 } { 4 }$ E) $\frac { 5 } { 4 }$
turkey-yks 2019 Q7 Verify Truth of Logarithmic Statements
In a Mathematics lesson, Canan performed operations by following the steps below in order. I. $\operatorname { step } \quad : \quad 6 = 1 \cdot 2 \cdot 3 = \mathrm { e } ^ { \ln 1 } \cdot \mathrm { e } ^ { \ln 2 } \cdot \mathrm { e } ^ { \ln 3 }$ II. $\operatorname { step } : \quad e ^ { \ln 1 } \cdot e ^ { \ln 2 } \cdot e ^ { \ln 3 } = e ^ { \ln 1 + \ln 2 + \ln 3 }$ III. step: $\quad e ^ { \ln 1 + \ln 2 + \ln 3 } = e ^ { \ln 6 }$ IV. $\operatorname { step } : : \mathrm { e } ^ { \ln 6 } = \mathrm { e } ^ { \ln ( 2 + 4 ) }$ V. step: $\mathrm { e } ^ { \ln ( 2 + 4 ) } = \mathrm { e } ^ { \ln 2 + \ln 4 }$ VI. $\operatorname { step } : \quad e ^ { \ln 2 + \ln 4 } = e ^ { \ln 2 } \cdot e ^ { \ln 4 }$ VII. step: $e ^ { \ln 2 } \cdot e ^ { \ln 4 } = 2 \cdot 4 = 8$
At the end of these steps, Canan obtained the result $6 = 8$. Accordingly, in which of the numbered steps did Canan make an error?
A) II
B) III
C) IV
D) V
E) VI
turkey-yks 2019 Q14 Solve a Logarithmic Equation
Let x be an integer greater than 1.
  • $\frac { 64 } { \mathrm { x } }$ is an integer,
  • $\frac { \ln 64 } { \ln x }$ is not an integer.

Accordingly, what is the sum of the values that x can take?
A) 40
B) 42
C) 48
D) 54
E) 56
turkey-yks 2019 Q15 Simplify or Evaluate a Logarithmic Expression
Ada calculates the value of $\log _ { 2 } n$ on her scientific calculator for every positive integer n where $\mathrm { n } \leq 32$, and observes that each value is either an integer or a decimal number. Ada writes down either the number itself if the value displayed on the screen is an integer, or the integer part of the number if it is a decimal, and then finds the sum of these numbers she wrote down. Accordingly, what is the result of the sum that Ada found?
A) 94
B) 97
C) 100
D) 103
E) 106
turkey-yks 2020 Q20 Solve a Logarithmic Equation
When a stick is divided into 4 equal parts, the length of each part is $\log_5(x)$ units, and when divided into 10 equal parts, the length of each part is $\log_5\left(\frac{x^2}{25}\right)$ units.
Accordingly, what is the length of the stick in units?
A) 5
B) 8
C) 10
D) 12
E) 15
turkey-yks 2020 Q21 Solve a Logarithmic Equation
Where $n$ is an integer and $1 < n < 100$,
$$\log_2\left(\log_3 n\right)$$
the value of this expression equals a positive integer. Accordingly, what is the sum of the values that $n$ can take?
A) 36
B) 45
C) 63
D) 72
E) 90
turkey-yks 2020 Q22 Verify Truth of Logarithmic Statements
Where $a$ and $b$ are positive real numbers different from 1,
$$\log_a 2 < 0 < \log_2 b$$
the inequality is satisfied. Accordingly, I. $a + b > 1$ II. $b - a > a$ III. $a \cdot b > 1$ Which of the following statements are always true?
A) Only I
B) Only II
C) I and II
D) I and III
E) II and III
turkey-yks 2021 Q13 Simplify or Evaluate a Logarithmic Expression
On a calculator, when an operation is performed, the machine displays the result as a whole number if the result is an integer, or displays the integer part along with the first two decimal places after the decimal point if the result is a decimal number.
When Nevzat performs the operation $\ln ( 9{,}6 )$ on this calculator, he sees the value 2.26 on the screen, and when he performs the operation $\ln ( 0{,}3 )$, he sees the value $-1{,}20$ on the screen.
When Nevzat performs the operation $\ln ( 0{,}5 )$ on this calculator, what value does he see on the screen?
A) $-0{,}61$
B) $-0{,}65$
C) $-0{,}69$
D) $-0{,}73$
E) $-0{,}77$
turkey-yks 2021 Q17 Analyze a Logarithmic Function (Limits, Monotonicity, Zeros, Extrema)
On the set of real numbers greater than 1, a function $f$ is defined as
$$f ( x ) = 3 \ln \left( x ^ { 2 } - 1 \right) + 2 \ln \left( x ^ { 3 } - 1 \right) - 5 \ln ( x - 1 )$$
Accordingly,
$$\lim _ { x \rightarrow 1 ^ { + } } e ^ { f ( x ) }$$
what is the value of this limit?
A) 30
B) 36
C) 60
D) 64
E) 72
turkey-yks 2023 Q23 Logarithmic Function Graph Intersection or Geometric Analysis
In the Cartesian coordinate plane, the graphs of functions $f(x) = \log_{2} x$ and $g(x) = \log_{\frac{1}{4}} x$ are given in the figure. Points $A$ and $D$ are on the graph of function $f$, and points $B$ and $C$ are on the graph of function $g$. In the figure, the line segment $[AB]$ passing through the point $(4, 0)$ and the line segment $[CD]$ are both perpendicular to the x-axis, and the area of triangle $ABC$ is 6 square units.
Accordingly, what is the area of triangle $ACD$ in square units?
A) 12 B) 11 C) 10 D) 9 E) 8
turkey-yks 2023 Q24 Solve a Logarithmic Equation
Let $x$ be a positive real number,
$$\log_{4}(x + 5) + \log_{4}(x + 4) - \log_{4}(x + 3) = \log_{2} 3$$
What is the value of $x$ that satisfies this equality?
A) $\sqrt{6}$ B) $\sqrt{7}$ C) $2\sqrt{2}$ D) $2\sqrt{5}$ E) $3\sqrt{2}$
turkey-yks 2024 Q13 Solve a Logarithmic Equation
Let $a$, $x$ and $y$ be positive real numbers. The numbers
$$\log_{a} x, \quad \log_{a} y, \quad \log_{a}(x+y)$$
arranged from smallest to largest are consecutive integers. What is the value of $\log_{a}(2a+1)$?
A) $-2$ B) $-1$ C) $2$ D) $3$ E) $4$
turkey-yks 2025 Q17 Solve a Logarithmic Equation
Let $a$ and $b$ be non-consecutive positive integers. The equality
$$\ln(a!) = \ln(b!) + 3 \cdot \ln 2 + 2 \cdot \ln 3 + \ln 7$$
is satisfied. Accordingly, what is the sum $a + b$?
A) 10 B) 13 C) 15 D) 18 E) 20
turkey-yks 2025 Q18 Solve a Logarithmic Equation
Let $a, b, c$ and $d$ be distinct positive real numbers. The sets $A$ and $B$ are defined as
$$\begin{aligned} & A = \left\{ \log_{2} a, \log_{2} b, \log_{2} c, \log_{2} d \right\} \\ & B = \left\{ \log_{\frac{1}{2}} a, \log_{\frac{1}{2}} b, \log_{\frac{1}{2}} c, \log_{\frac{1}{2}} d \right\} \end{aligned}$$
$$\begin{aligned} & s(A \cap B) = 3 \\ & a \cdot b \cdot c \cdot d = \frac{7}{5} \\ & a + b + c + d = \frac{38}{5} \end{aligned}$$
Given that, what is the sum $a^{2} + b^{2} + c^{2} + d^{2}$?
A) 20 B) 22 C) 24 D) 26 E) 28