Mixed Degree Systems — Cumulative exam Answers

What is the simplified form of the following expression?

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.

For which rational expression is –5 an excluded value of x?

Which expression is equivalent to the following complex fraction?

Galena is solving the following system.Step 1: She multiplies equation (3) by 3 and adds it to equation (1). Step 2: She multiplies equation (3) by –7 and adds it to equation (2). Which statement explains Galena’s mistake?