Calculate (2/3)^-4: Solving Negative Power of a Fraction

Negative Exponents with Fractional Bases

(23)4=? (\frac{2}{3})^{-4}=\text{?}

❤️ Continue Your Math Journey!

We have hundreds of course questions with personalized recommendations + Account 100% premium

Step-by-step video solution

Watch the teacher solve the problem with clear explanations
00:00 Solve the following problem
00:03 According to the laws of exponents, fraction (A\B) to the power of (-N)
00:06 equals fraction (B\A) to the power of (N)
00:10 Let's apply this to our question
00:13 We obtain the fraction (3\2) to the power of (4)
00:17 According to the laws of exponents, any fraction to the power of (N)
00:20 is equal to the numerator to the power of (N) divided by the denominator to the power of (N)
00:23 Let's apply this to the question
00:26 We obtained (3) to the power of 4 divided by (2) to the power of 4
00:29 Let's solve 3 to the power of 4 using the laws of exponents
00:34 Let's solve 2 to the power of 4 using the laws of exponents
00:41 Insert the results
00:46 This is the solution

Step-by-step written solution

Follow each step carefully to understand the complete solution
1

Understand the problem

(23)4=? (\frac{2}{3})^{-4}=\text{?}

2

Step-by-step solution

We use the formula:

(ab)n=(ba)n (\frac{a}{b})^{-n}=(\frac{b}{a})^n

Therefore, we obtain:

(32)4 (\frac{3}{2})^4

We use the formula:

(ba)n=bnan (\frac{b}{a})^n=\frac{b^n}{a^n}

Therefore, we obtain:

3424=3×3×3×32×2×2×2=8116 \frac{3^4}{2^4}=\frac{3\times3\times3\times3}{2\times2\times2\times2}=\frac{81}{16}

3

Final Answer

8116 \frac{81}{16}

Key Points to Remember

Essential concepts to master this topic
  • Rule: Negative exponent flips the fraction and makes exponent positive
  • Technique: (23)4=(32)4 (\frac{2}{3})^{-4} = (\frac{3}{2})^4 then calculate normally
  • Check: Multiply result by original base raised to positive power: 8116×(23)4=1 \frac{81}{16} \times (\frac{2}{3})^4 = 1

Common Mistakes

Avoid these frequent errors
  • Making the entire result negative
    Don't think the negative exponent makes the answer negative = 8116 -\frac{81}{16} ! Negative exponents only flip fractions, they don't make results negative. Always remember that negative exponents create reciprocals, not negative numbers.

Practice Quiz

Test your knowledge with interactive questions

\( \)Choose the corresponding expression:

\( \left(\frac{1}{2}\right)^2= \)

FAQ

Everything you need to know about this question

Why does a negative exponent flip the fraction?

+

A negative exponent means "take the reciprocal and use the positive exponent". So (23)4 (\frac{2}{3})^{-4} becomes (32)4 (\frac{3}{2})^4 - we flip first, then calculate!

How do I calculate (32)4 (\frac{3}{2})^4 step by step?

+

Use the rule (ab)n=anbn (\frac{a}{b})^n = \frac{a^n}{b^n} . So (32)4=3424=8116 (\frac{3}{2})^4 = \frac{3^4}{2^4} = \frac{81}{16} . Calculate top and bottom separately: 34=81 3^4 = 81 and 24=16 2^4 = 16 .

Will the answer always be bigger than 1 with negative exponents?

+

When the original fraction is less than 1 (like 23 \frac{2}{3} ), flipping it gives a fraction greater than 1, so yes! But if you started with 53 \frac{5}{3} , flipping would give 35 \frac{3}{5} (less than 1).

What's the difference between (23)4 (\frac{2}{3})^{-4} and (23)4 -(\frac{2}{3})^4 ?

+

Huge difference! (23)4=8116 (\frac{2}{3})^{-4} = \frac{81}{16} (positive), but (23)4=1681 -(\frac{2}{3})^4 = -\frac{16}{81} (negative). The placement of the negative sign completely changes the meaning!

🌟 Unlock Your Math Potential

Get unlimited access to all 18 Exponents Rules questions, detailed video solutions, and personalized progress tracking.

📹

Unlimited Video Solutions

Step-by-step explanations for every problem

📊

Progress Analytics

Track your mastery across all topics

🚫

Ad-Free Learning

Focus on math without distractions

No credit card required • Cancel anytime

More Questions

Click on any question to see the complete solution with step-by-step explanations