Logarithmic equations and inequalities

1003159004

Level: 
B
Which of the given numbers is the sum of all the solutions of the equations \( \text{(1)} \) and \( \text{(2)} \)? \[ \begin{aligned} 10^{x-1}&=2 &\text{(1)} \\ 2^{1-x}&=5^x &\text{(2)} \end{aligned} \]
\( \log⁡40 \)
\( \log⁡22 \)
\( \log12+\log_7⁡2 \)
\( \log12-\log_7⁡2 \)

1003162704

Level: 
B
Which of the following statements about the given equation is true? \[ \log_4(x-1)^2=3-\frac1{\log_4⁡(x-1)} \]
The solution set consists of two prime numbers.
The solution set is \( \left\{\frac12;1\right\} \).
The solution set is the empty set.
The equation has exactly one solution.
None of the above statements is true.

1003177802

Level: 
B
Choose the domain of the expression \( \ln\!⁡\left(-|3-2x|+6\right) \).
\( \left(-\frac32;\frac92\right) \)
\( \left(-\infty;-\frac32\right)\cup\left(\frac92;\infty\right) \)
\( \left(-\infty;\frac32\right)\cup\left(\frac92;\infty\right) \)
\( \left(\frac92;\infty\right) \)