Powers of Negative Numbers Practice Problems and Solutions

Master negative number exponentiation with step-by-step practice problems. Learn even vs odd power rules, parentheses placement, and solve real examples.

πŸ“šMaster Powers of Negative Numbers with Interactive Practice
  • Determine whether negative numbers raised to even powers give positive results
  • Calculate negative numbers raised to odd powers correctly
  • Distinguish between (-x)ⁿ and -xⁿ using parentheses rules
  • Apply exponent laws to solve complex negative number expressions
  • Identify common mistakes in negative number exponentiation
  • Build confidence solving multi-step problems with negative bases

Understanding Powers of Negative Numbers

Complete explanation with examples

Exponentiation of Negative Numbers

Negative number raised to an even power

Raising any negative number to an even power will result in a positive outcome.
When nn is even:
(βˆ’x)n=xn(-x)^n=x^n

Negative number raised to an odd power

Raising any negative number to an odd power will result in a negative outcome.
When nn is odd:
(βˆ’x)n=βˆ’(x)n(-x)^n=-(x)^n

What is the difference between a power that is inside parentheses and one that is outside of them?

When the exponent is outside the parentheses - it applies to everything inside them.
When the exponent is inside the parentheses - it applies only to its base and not to the minus sign that precedes it.

Detailed explanation

Practice Powers of Negative Numbers

Test your knowledge with 17 quizzes

\( \)\( (-3)^4= \)

Examples with solutions for Powers of Negative Numbers

Step-by-step solutions included
Exercise #1

(βˆ’2)7= (-2)^7=

Step-by-Step Solution

To solve for (βˆ’2)7(-2)^7, follow these steps:

  • Step 1: Identify the base and the exponent given in the expression, which are βˆ’2-2 and 77, respectively.
  • Step 2: Recognize that since the exponent is 77, which is an odd number, the result of the power will remain negative: (βˆ’2)7(-2)^7 will be βˆ’(27)- (2^7).
  • Step 3: Compute 272^7. This involves multiplying 22 by itself 77 times:
    2Γ—2=42 \times 2 = 4
    4Γ—2=84 \times 2 = 8
    8Γ—2=168 \times 2 = 16
    16Γ—2=3216 \times 2 = 32
    32Γ—2=6432 \times 2 = 64
    64Γ—2=12864 \times 2 = 128
    Thus, 27=1282^7 = 128.
  • Step 4: Apply the negative sign to the result of 272^7, resulting in βˆ’128-128.

Therefore, the value of (βˆ’2)7(-2)^7 is βˆ’128-128.

Answer:

βˆ’128 -128

Video Solution
Exercise #2

βˆ’(2)2= -(2)^2=

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Calculate (2)2 (2)^2
  • Step 2: Apply the negative sign

Now, let's work through each step:
Step 1: Calculate (2)2 (2)^2 . This is equal to 2Γ—2=4 2 \times 2 = 4 .
Step 2: Apply the negative sign: The expression βˆ’(2)2-(2)^2 now becomes βˆ’4-4.

Therefore, the value of the expression βˆ’(2)2-(2)^2 is βˆ’4 -4 .

This matches choice 4, which is βˆ’4 -4 .

Answer:

βˆ’4 -4

Video Solution
Exercise #3

Solve the following expression:

(βˆ’8)2= (-8)^2=

Step-by-Step Solution

When we have a negative number raised to a power, the location of the minus sign is very important.

If the minus sign is inside or outside the parentheses, the result of the exercise can be completely different.

When the minus sign is inside the parentheses, our exercise will look like this:

(-8)*(-8)=

Since we know that minus times minus is actually plus, the result will be positive:

(-8)*(-8)=64

Answer:

64 64

Video Solution
Exercise #4

8= 8=

Step-by-Step Solution

To solve this problem, let's evaluate both given expressions to determine which results in 8.

  • Step 1: Evaluate (βˆ’2)3(-2)^3:
    (βˆ’2)3=(βˆ’2)Γ—(βˆ’2)Γ—(βˆ’2)(-2)^3 = (-2) \times (-2) \times (-2).
    Multiplying across: (βˆ’2)Γ—(βˆ’2)=4(-2) \times (-2) = 4, and then 4Γ—(βˆ’2)=βˆ’84 \times (-2) = -8.
    Thus, (βˆ’2)3=βˆ’8(-2)^3 = -8.
  • Step 2: Evaluate βˆ’(βˆ’2)3-(-2)^3:
    First, calculate (βˆ’2)3(-2)^3 again: We already know (βˆ’2)3=βˆ’8(-2)^3 = -8.
    Now, apply the negative sign: βˆ’(βˆ’8)=8-(-8) = 8.

Therefore, the expression that equals 88 is βˆ’(βˆ’2)3-(-2)^3.

Thus, the correct expression that evaluates to 8 is βˆ’(βˆ’2)3-(-2)^3.

Answer:

βˆ’(βˆ’2)3 -(-2)^3

Video Solution
Exercise #5

βˆ’16= -16=

Step-by-Step Solution

To solve this problem, we'll need to carefully consider the placement of parentheses and the order of operations when dealing with negative numbers and exponentiation:

  • Step 1: Examine the given expression (βˆ’4)2(-4)^2. This indicates squaring the entire negative four, which results in 1616.
  • Step 2: Now, examine βˆ’(βˆ’4)2-(-4)^2 paying close attention to the negative sign in front. (βˆ’4)2(-4)^2 again results in 1616, but placing a minus before it changes its sign to βˆ’16-16.

Let's analyze each possible choice:

  • For choice 1: The expression is βˆ’(βˆ’4)2-(-4)^2. Calculating (βˆ’4)2(-4)^2 gives 1616, and applying the negative sign outside results in the expression value of βˆ’16-16.
  • For choice 2: The expression is (βˆ’4)2(-4)^2, calculated to give 1616.

Therefore, the expression that correctly equals βˆ’16-16 is choice 1, represented by βˆ’(βˆ’4)2-(-4)^2.

The correct answer is choice 1: βˆ’(βˆ’4)2-(-4)^2.

Answer:

βˆ’(βˆ’4)2 -(-4)^2

Video Solution

Frequently Asked Questions

What happens when you raise a negative number to an even power?

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When a negative number is raised to an even power, the result is always positive. For example, (-3)Β² = 9 because (-3) Γ— (-3) = 9. This follows the rule that negative times negative equals positive.

Why do negative numbers raised to odd powers stay negative?

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Negative numbers raised to odd powers remain negative because you multiply an odd number of negative values. For instance, (-2)Β³ = (-2) Γ— (-2) Γ— (-2) = -8, where the final multiplication involves one negative factor.

What's the difference between (-4)Β² and -4Β²?

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(-4)Β² equals 16 because the exponent applies to the entire negative number in parentheses. However, -4Β² equals -16 because the exponent only applies to 4, then the negative sign is applied afterward.

How do parentheses affect negative number exponentiation?

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Parentheses determine what the exponent applies to: β€’ With parentheses: (-x)ⁿ means the exponent applies to the entire negative number β€’ Without parentheses: -xⁿ means the exponent applies only to x, then add the negative sign

What are the most common mistakes with negative number powers?

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Common errors include: 1) Forgetting that even powers of negatives are positive, 2) Misapplying exponents when parentheses are missing, 3) Confusing (-x)ⁿ with -xⁿ notation.

How do you solve complex expressions like (-2)⁴ - 3²?

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Solve step by step: First, calculate (-2)⁴ = 16 (even power makes it positive). Then calculate 3² = 9. Finally, compute 16 - 9 = 7. Remember to follow order of operations.

When do negative base exponents appear in real life?

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Negative base exponents appear in physics (alternating currents), finance (debt calculations), and temperature changes. Understanding these rules helps solve problems involving periodic patterns and directional quantities.

What grade level typically learns powers of negative numbers?

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Powers of negative numbers are typically introduced in 8th grade algebra and reinforced in high school algebra courses. Students should first master basic exponent rules and integer operations before tackling this concept.

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