Math Problem Statement

(2^(-1) × 4^(-1) ) ÷ 2^(-2) = ? 2 1/2 1/4 4

Solution

Let's break this down step by step:

The given expression is:

21×4122\frac{2^{-1} \times 4^{-1}}{2^{-2}}

Step 1: Simplify the exponents

  • 21=122^{-1} = \frac{1}{2}
  • 41=144^{-1} = \frac{1}{4}, and since 4=224 = 2^2, we can write 41=(22)1=224^{-1} = (2^2)^{-1} = 2^{-2}.
  • 22=122=142^{-2} = \frac{1}{2^2} = \frac{1}{4}

So the expression now looks like:

(12×14)22\frac{\left( \frac{1}{2} \times \frac{1}{4} \right)}{2^{-2}}

Step 2: Multiply the terms in the numerator

12×14=18\frac{1}{2} \times \frac{1}{4} = \frac{1}{8}

Thus, the expression becomes:

1822=1814\frac{\frac{1}{8}}{2^{-2}} = \frac{\frac{1}{8}}{\frac{1}{4}}

Step 3: Divide fractions

To divide fractions, multiply the numerator by the reciprocal of the denominator:

18÷14=18×4=48=12\frac{1}{8} \div \frac{1}{4} = \frac{1}{8} \times 4 = \frac{4}{8} = \frac{1}{2}

Final Answer:

12\boxed{\frac{1}{2}}

Do you want any further details or have any questions?

Here are 5 related questions:

  1. How do negative exponents affect the value of a number?
  2. What is the rule for dividing exponents with the same base?
  3. How can you convert powers of larger numbers like 44 into powers of 22?
  4. How do you multiply and divide fractions in algebraic expressions?
  5. What is the reciprocal of a fraction and when is it used?

Tip: When working with negative exponents, remember that an=1ana^{-n} = \frac{1}{a^n}, which can help simplify complex expressions.

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Math Problem Analysis

Mathematical Concepts

Exponents
Negative Exponents
Fractions
Division of Powers

Formulas

a^(-n) = 1 / a^n
Multiplying fractions: (a/b) × (c/d) = (a×c)/(b×d)
Dividing fractions: (a/b) ÷ (c/d) = (a/b) × (d/c)

Theorems

Negative exponent rule: a^(-n) = 1 / a^n
Reciprocal of a fraction: a/b = 1/(b/a)

Suitable Grade Level

Grades 8-10