Cumulative Exam — Cumulative exam Answers

What are the excluded values of x for ?

The magnitude, M, of an earthquake is defined to be , where I is the intensity of the earthquake (measured by the amplitude of the seismograph wave) and S is the intensity of a “standard” earthquake, which is barely detectable. What is the magnitude of an earthquake that is 1,000 times more intense than a standard earthquake? Use a calculator. Round your answer to the nearest tenth.

What is the solution to the equation ?

For the inverse variation equation , what is the value of p when V = ?

The excluded values of a rational expression are –3, 0, and 8. Which of the following could be this expression?

If , what is the value of x?

Which of the following shows the extraneous solution to the logarithmic equation below?

If , what is the value of x?

One brand of vinegar has a pH of 4.5. Another brand has a pH of 5.0. The equation for the pH of a substance is pH = –log[H+], where H+ is the concentration of hydrogen ions. What is the approximate difference in the concentration of hydrogen ions between the two brands of vinegar?

Haji rows his canoe 10 mph in still water. He noticed one day that he could row 4 miles upstream in the same amount of time he could row 6 miles downstream. What was the approximate speed of the current that day?

What is the solution, if any, to the inequality ?

Mrs. Cho wrote the following problem on the board.Problem: Step 1: Step 2: Step 3: What should Mrs. Cho do next?

For what value of x does ?

The graph of a quadratic inequality is shown.

Which expression is equivalent to the following complex fraction?

The intensity, or loudness, of a sound can be measured in decibels (dB), according to the equation , where I is the intensity of a given sound and I0 is the threshold of hearing intensity. What is the intensity, in decibels, [I(dB)], when ?

Sharon is jumping from an 18-foot diving board with an initial upward velocity of 4 ft/s. When Sharon jumps, Megan throws a beach ball up to Sharon with an initial upward velocity of 16 ft/s from a height 5 feet off the ground. To the nearest hundredth of a second, how long after she jumps does the ball reach Sharon?

A chemist has 500 mL of a 30% acid solution. She adds x milliliters of a 10% acid solution. Which statement is true about the graph of the function that represents the concentration of the final solution?

An initial investment of $200 is now valued at $350. The annual interest rate is 8% compounded continuously. The equation represents the situation, where t is the number of years the money has been invested. About how long has the money been invested? Use a calculator and round your answer to the nearest whole number.

A biologist begins working with a sample containing 20,000 bacteria. The population size doubles every 10 days according to the equation , where t represents the number of days. After seven days the biologist begins working with a second sample of 20,000 bacteria. The equation used to represent the population of sample 2 after t days is . Which of the following is an equivalent form of the equation for the population of sample 2?