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*Read the following SAT test question and then select your answer.*

*Remember to follow the Knowsys Method: read carefully, identify the bottom line, assess your options, attack the problem, and loop back to ensure that you answered the question correctly.*

*If , which of the following must be equivalent to*

**x**?After reading, find the bottom line and note it at the top of your scratch work.

*x=?***Next, assess your options. There are two courses of action apparent here: you could pick numbers and plug them into**

*x*and

*y*, or you could apply the exponent rules to solve for

*x*. Which would be faster and easier? The exponent rules.

What can you do here? Since you need to isolate

*x*, pay attention to its exponent. Normally, a fraction in an exponent indicates that you need to take a root--in this case, a cube root--but since you cannot take the root of a variable, do the opposite. Cube both sides.

The rule for "power to a power" situations, when an exponent is itself the base of another exponent, is to simply multiply the powers together.

Loop back to your bottom line. You were looking for

*x*, and you found that . Now look at the answer choices.

The answer is E.

On sat.collegeboard.org, 50% of responses were correct.

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