Powers of Negative Numbers - Examples, Exercises and Solutions

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:
(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:
(x)n=(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 9 quizzes

\( \)\( (-1)^{99}= \)

Examples with solutions for Powers of Negative Numbers

Step-by-step solutions included
Exercise #1

(2)7= (-2)^7=

Step-by-Step Solution

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

  • Step 1: Identify the base and the exponent given in the expression, which are 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: (2)7(-2)^7 will be (27)- (2^7).
  • Step 3: Compute 272^7. This involves multiplying 22 by itself 77 times:
    2×2=42 \times 2 = 4
    4×2=84 \times 2 = 8
    8×2=168 \times 2 = 16
    16×2=3216 \times 2 = 32
    32×2=6432 \times 2 = 64
    64×2=12864 \times 2 = 128
    Thus, 27=1282^7 = 128.
  • Step 4: Apply the negative sign to the result of 272^7, resulting in 128-128.

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

Answer:

128 -128

Video Solution
Exercise #2

(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 2×2=4 2 \times 2 = 4 .
Step 2: Apply the negative sign: The expression (2)2-(2)^2 now becomes 4-4.

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

This matches choice 4, which is 4 -4 .

Answer:

4 -4

Video Solution
Exercise #3

9= 9=

Step-by-Step Solution

To solve this problem, we need to evaluate expressions by applying the rules of exponents and the effects of parentheses on negative numbers:

  • (3)2(-3)^2: When a negative number is squared, the result is positive. So, (3)2(-3)^2 means 3×3=9-3 \times -3 = 9.
  • (3)2-(-3)^2: This means 1×(3×3)-1 \times (-3 \times -3) because squaring a number negates the negative sign inside parentheses, resulting in 9-9.
  • (3)2-(3)^2: This equals 1×(3×3)=9-1 \times (3 \times 3) = -9, as the negative sign is outside the squared value.
  • 3-3: This is simply 3-3.

Only (3)2(-3)^2 equals 9, confirming it as the correct expression required by the problem.

Therefore, the solution to the problem is (3)2 (-3)^2 .

Answer:

(3)2 (-3)^2

Video Solution
Exercise #4

Solve the following expression:

(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 #5

(7)2= -(7)^2=

Step-by-Step Solution

The given problem asks us to evaluate the expression (7)2 -(7)^2 . To solve this, we must correctly handle the operations of exponentiation and negation.

Firstly, examine (7)2(7)^2:
- (7)2(7)^2 means multiplying 7 by itself.
- Calculating this gives: 7×7=49 7 \times 7 = 49 .

Next, apply the negative sign to the result:
- The expression (7)2-(7)^2 indicates that we apply the negative sign to the result of (7)2(7)^2.
- Therefore, multiply the result by 1-1:
1×49=49-1 \times 49 = -49.

Thus, the correct evaluation of the expression is 49-49.

Thus, the solution to this problem is 49 -49 .

Answer:

49 -49

Video Solution

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