Simplify x^(-2/3) and Find Square Root

Published on February 28, 2026

Algebra

Solve for x given x = (27/125)^(-2/3) and then calculate the value of sqrt(x) using exponent rules.

Question

Answer

Here is the step-by-step solution to the problem.
The problem asks to find the value of given that:
Step 1: Simplify the expression for .
We use the property of exponents that and .
Next, we express the numerator and the denominator as powers with an exponent of 3, since the denominator of the exponent is 3:
So,
Substitute this back into the expression for :
Using the property of exponents :
Step 2: Calculate .
We need to find :
Since , and is positive:
Alternative Method (Calculating directly):
We know that .
Using the property :
Apply the negative exponent rule :
The exponent means taking the cube root:
Since and :
Conclusion:
The value of is , which corresponds to option (a).
The final answer is:

Theorems

• Negative Exponent Rule (Reciprocal)

For any non-zero number and any real number , . For fractions, .

• Power of a Power Rule

For any real number and any real numbers and , .

• Fractional Exponent Rule (Cube Root)

For any real number , .

• Power of a Quotient Rule

For any real numbers and (with ) and any real number , .

• Square Root of a Square

For any real number , . Since the result is positive, .