Examples with solutions for Multiplication of Powers: Presenting powers with negative exponents as fractions

Exercise #1

Reduce the following equation:

112×115×114= 11^{-2}\times11^{-5}\times11^{-4}=

Video Solution

Step-by-Step Solution

To solve the expression 112×115×114 11^{-2} \times 11^{-5} \times 11^{-4} , we apply the rules for multiplying numbers with the same base:

  • Step 1: Use the rule for multiplying powers with the same base: am×an=am+n a^m \times a^n = a^{m+n} .

  • Step 2: Add the exponents: 2+5+4-2 + -5 + -4.

  • Step 3: Perform the calculation: 254=11-2 - 5 - 4 = -11.

  • Step 4: Write the expression with the combined exponent: 111111^{-11}.

  • Step 5: Express 111111^{-11} as a positive power using the property of negative exponents: an=1ana^{-n} = \frac{1}{a^n}.

Therefore, 1111=1111111^{-11} = \frac{1}{11^{11}}.

The final answer is 11111\frac{1}{11^{11}}.

Answer

11111 \frac{1}{11^{11}}

Exercise #2

Insert the corresponding expression:

91×92×93= 9^{-1}\times9^{-2}\times9^{-3}=

Video Solution

Step-by-Step Solution

To solve the problem 91×92×93 9^{-1} \times 9^{-2} \times 9^{-3} , we follow these steps:

  • Step 1: Use the rule for multiplying exponential terms with the same base. The formula is am×an=am+n a^m \times a^n = a^{m+n} .
  • Step 2: Apply the formula to the given expression: 91×92×93=9123 9^{-1} \times 9^{-2} \times 9^{-3} = 9^{-1-2-3} .
  • Step 3: Simplify the exponent: 123=6 -1 - 2 - 3 = -6 . Therefore, 91×92×93=96 9^{-1} \times 9^{-2} \times 9^{-3} = 9^{-6} .

We can express 96 9^{-6} as a positive power by recalling that negative exponents indicate reciprocals:

96=196 9^{-6} = \frac{1}{9^6} .

Thus, both 96 9^{-6} and 196 \frac{1}{9^6} are valid expressions for the simplified form. Additionally, the expression 9123 9^{-1-2-3} highlights the step where we combined the exponents, and it is equivalent to the final result. Therefore, all given answers correctly represent the simplified expression.

Therefore, the solution to the problem is All answers are correct.

Answer

All answers are correct

Exercise #3

Insert the corresponding expression:

810×85×89= 8^{-10}\times8^{-5}\times8^9=

Video Solution

Step-by-Step Solution

To solve this problem, we need to simplify the expression 810×85×89 8^{-10} \times 8^{-5} \times 8^9 using exponent rules.

  • Step 1: Apply the multiplication rule for exponents. This rule states that when multiplying expressions with the same base, you add their exponents. Thus, we calculate:
    810×85×89=810+(5)+9 8^{-10} \times 8^{-5} \times 8^9 = 8^{-10 + (-5) + 9} .
  • Step 2: Simplify the exponents:
    10+(5)+9=105+9=6 -10 + (-5) + 9 = -10 - 5 + 9 = -6 .
  • Step 3: The expression simplifies to:
    86 8^{-6} .
  • Step 4: Convert the negative exponent into a positive one by using the rule for negative exponents, where an=1an a^{-n} = \frac{1}{a^n} :
    86=186 8^{-6} = \frac{1}{8^6} .

Therefore, the simplified expression is 186 \frac{1}{8^6} .

The corresponding expression is:

186 \frac{1}{8^6}

Answer

186 \frac{1}{8^6}

Exercise #4

Insert the corresponding expression:

46×4= 4^{-6}\times4=

Video Solution

Step-by-Step Solution

To simplify the expression 46×44^{-6} \times 4, follow these steps:

  • Step 1: Apply the rule for multiplying powers with the same base, which is am×an=am+na^m \times a^n = a^{m+n}.

  • Step 2: Identify the exponents for the terms. Here, we have 464^{-6} and 414^1, implying m=6m = -6 and n=1n = 1.

  • Step 3: Add the exponents: (6)+1=5(-6) + 1 = -5. Thus, we have 46×41=454^{-6} \times 4^1 = 4^{-5}.

  • Step 4: Recognize that a negative exponent indicates a reciprocal. Therefore, 45=1454^{-5} = \frac{1}{4^5}.

Therefore, the solution to the expression 46×44^{-6} \times 4 is 145 \frac{1}{4^5} .

Answer

145 \frac{1}{4^5}

Exercise #5

Insert the corresponding expression:

58×56= 5^{-8}\times5^6=

Video Solution

Step-by-Step Solution

Let's simplify the expression 58×565^{-8} \times 5^6 using the rules of exponents.

  • Step 1: Apply the rule for multiplying powers with the same base. According to this rule, when multiplying like bases, we add the exponents: 58×56=58+65^{-8} \times 5^6 = 5^{-8 + 6}
  • Step 2: Calculate the sum of the exponents: 8+6=2-8 + 6 = -2.
  • Step 3: Write the simplified expression: 525^{-2}.
  • Step 4: Relate the expression to the given choices:

The simplified expression 525^{-2} corresponds to choice 1. Additionally, rewriting a negative exponent using the fraction format gives: 52=1525^{-2} = \frac{1}{5^2}, which matches choice 2.

Thus, both choices 'a: 525^{-2}' and 'b: 152\frac{1}{5^2}' are correct.

Therefore, according to the given answer choice, a'+b' are correct.

Answer

a'+b' are correct

More Questions