Logarithm — Quiz 4

Questions in this quiz (6)

1. If $$\log_3 x = 4m - 3n$$, what is $$x$$?

   • $$\frac{9^m}{27^n}$$
   • $$\frac{81^m}{27^n}$$
   • $$\frac{3^m}{9^n}$$
   • $$\frac{9^m}{3^n}$$

2. Find all real solutions of $$\log_3 81 - \log_3 9 = \log_2 x.$$

   • 81
   • 9
   • 4
   • 3

3. If $$\log a = 2 + c$$, which of these is $$a$$?

   • $$100 \times 10^c$$
   • $$1000 \times 10^c$$
   • $$1000c$$
   • $$10^c$$

4. If $$\log a = 5 + \log 6.2$$, what is $$a$$?

   • $$620,500$$
   • $$620,000$$
   • $$62,500$$
   • $$6,250,000$$

5. Which of these is the domain of $$\log(x^2-4x-21)?$$

   • $$-3$$<$$x$$<$$7$$
   • $$x\leq-3$$ or $$x\geq7$$
   • $$x$$<$$-3$$ or $$x$$>$$7$$
   • $$-3\leq x\leq7$$

6. Which of the following values for $$x$$ makes $$\log_4 8 + \log_4 x = 3$$ true?

   • 4
   • 64
   • 12
   • 8