Math Problem Statement

(0.04)^(-1.5) - (0.125)^(-2/3)

Solution

The given mathematical expression in the image is:

(0.04)1.5(0.125)23(0.04)^{-1.5} - (0.125)^{-\frac{2}{3}}

Step 1: Evaluate each term separately

  1. Evaluate (0.04)1.5(0.04)^{-1.5}:

    • Rewrite 0.040.04 as 125\frac{1}{25}, so: (0.04)1.5=(125)1.5(0.04)^{-1.5} = \left(\frac{1}{25}\right)^{-1.5}
    • Using the rule an=1ana^{-n} = \frac{1}{a^n}, this becomes: (125)1.5=251.5\left(\frac{1}{25}\right)^{-1.5} = 25^{1.5}
    • 251.5=253=53=12525^{1.5} = \sqrt{25}^3 = 5^3 = 125.

    So, (0.04)1.5=125(0.04)^{-1.5} = 125.

  2. Evaluate (0.125)23(0.125)^{-\frac{2}{3}}:

    • Rewrite 0.1250.125 as 18\frac{1}{8}, so: (0.125)23=(18)23(0.125)^{-\frac{2}{3}} = \left(\frac{1}{8}\right)^{-\frac{2}{3}}
    • Using the rule an=1ana^{-n} = \frac{1}{a^n}, this becomes: (18)23=823\left(\frac{1}{8}\right)^{-\frac{2}{3}} = 8^{\frac{2}{3}}
    • 823=(83)2=22=48^{\frac{2}{3}} = (\sqrt[3]{8})^2 = 2^2 = 4.

    So, (0.125)23=4(0.125)^{-\frac{2}{3}} = 4.

Step 2: Combine results

Now substitute the values back into the original expression:

(0.04)1.5(0.125)23=1254=121(0.04)^{-1.5} - (0.125)^{-\frac{2}{3}} = 125 - 4 = 121

Final Answer:

121\boxed{121}

Would you like more details on the calculations or further examples?

Related Questions:

  1. What are the steps to calculate fractional exponents like am/na^{m/n}?
  2. How do negative exponents work with fractions?
  3. Can you explain how to simplify complex fractional bases like 0.040.04?
  4. How can we rewrite numbers in different forms to simplify calculations?
  5. What are common mistakes to avoid when dealing with fractional and negative exponents?

Tip:

Always rewrite numbers in fractional or exponential form to simplify calculations with exponents.

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Math Problem Analysis

Mathematical Concepts

Negative Exponents
Fractional Exponents
Simplification of Numbers

Formulas

a^(-n) = 1 / a^n
a^(m/n) = (n-th root of a)^m

Theorems

Exponentiation Rules

Suitable Grade Level

Grades 9-12