Exponents and Roots

What is an exponent?

An exponent tells us the amount of times a number is to be multiplied by itself.

What is a root?

A root is the inverse operation of exponentiation, which helps us discover which number multiplied by itself gives this result.

The square root is equal to the power of 0.5.

Exponents and the Base of the Exponents

Practice Powers and Roots - Basic

Examples with solutions for Powers and Roots - Basic

Exercise #1

Choose the expression that is equal to the following:

27 2^7

Video Solution

Step-by-Step Solution

To solve this problem, we'll focus on expressing the power 27 2^7 as a series of multiplications.

  • Step 1: Identify the given power expression 27 2^7 .
  • Step 2: Convert 27 2^7 into a product of repeated multiplication. This involves writing 2 multiplied by itself for a total of 7 times.
  • Step 3: The expanded form of 27 2^7 is 2×2×2×2×2×2×2 2 \times 2 \times 2 \times 2 \times 2 \times 2 \times 2 .

By comparing this expanded form with the provided choices, we see that the correct expression is:

2222222 2\cdot2\cdot2\cdot2\cdot2\cdot2\cdot2

Therefore, the solution to the problem is the expression that matches this expanded multiplication form, which is the choice 1: 2222222\text{1: } 2\cdot2\cdot2\cdot2\cdot2\cdot2\cdot2.

Answer

2222222 2\cdot2\cdot2\cdot2\cdot2\cdot2\cdot2

Exercise #2

Which of the following is equivalent to the expression below?

10,0001 10,000^1

Video Solution

Step-by-Step Solution

To solve this problem, we will apply the rule of exponents:

  • Any number raised to the power of 1 remains unchanged. Therefore, by the identity property of exponents, 10,0001=10,000 10,000^1 = 10,000 .

Given the choices:

  • 10,00010,000 10,000 \cdot 10,000 : This is 10,0002 10,000^2 .
  • 10,0001 10,000 \cdot 1 : Simplifying this expression yields 10,000, which is equivalent to 10,0001 10,000^1 .
  • 10,000+10,000 10,000 + 10,000 : This results in 20,000, not equivalent to 10,0001 10,000^1 .
  • 10,00010,000 10,000 - 10,000 : This results in 0, not equivalent to 10,0001 10,000^1 .

Therefore, the correct choice is 10,0001 10,000 \cdot 1 , which simplifies to 10,000, making it equivalent to 10,0001 10,000^1 .

Thus, the expression 10,0001 10,000^1 is equivalent to:

10,0001 10,000 \cdot 1

Answer

10,0001 10,000\cdot1

Exercise #3

Choose the largest value

Video Solution

Step-by-Step Solution

Let's begin by calculating the numerical value of each of the roots in the given options:

25=516=49=3 \sqrt{25}=5\\ \sqrt{16}=4\\ \sqrt{9}=3\\ We can determine that:

5>4>3>1 Therefore, the correct answer is option A

Answer

25 \sqrt{25}

Exercise #4

49= \sqrt{49}=

Video Solution

Step-by-Step Solution

To solve this problem, we follow these steps:

  • Step 1: Understand that finding the square root of a number means determining what number, when multiplied by itself, equals the original number.
  • Step 2: Identify the numbers that could potentially be the square root of 4949. These are ±7 \pm7, but by convention, the square root function typically refers to the non-negative root.
  • Step 3: Calculate 7×7=497 \times 7 = 49. This confirms that 49=7 \sqrt{49} = 7.
  • Step 4: Verify using the problem's multiple-choice answers to ensure 77 is among them, confirming choice number .

Therefore, the solution to the problem 49 \sqrt{49} is 7 7 .

Answer

7

Exercise #5

62= 6^2=

Video Solution

Step-by-Step Solution

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

  • Step 1: Recognize that 62 6^2 means 6×6 6 \times 6 .
  • Step 2: Perform the multiplication of 6 by itself.

Now, let's work through each step:
Step 1: The expression 62 6^2 indicates we need to multiply 6 by itself.
Step 2: Calculating 6×6 6 \times 6 gives us 36.

Therefore, the value of 62 6^2 is 36.

Answer

36

Exercise #6

112= 11^2=

Video Solution

Step-by-Step Solution

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

  • Step 1: Set up the multiplication as 11×11 11 \times 11 .
  • Step 2: Compute the product using basic arithmetic.
  • Step 3: Compare the result with the provided multiple-choice answers to identify the correct one.

Now, let's work through each step:
Step 1: We begin with the calculation 11×11 11 \times 11 .
Step 2: Perform the multiplication:

  1. Multiply the units digits: 1×1=1 1 \times 1 = 1 .
  2. Next, for the tens digits: 11×10=110 11 \times 10 = 110 .
  3. Add the results: 110+1=111 110 + 1 = 111 . This doesn't seem right, so let's break it down further.

Let's examine a more structured multiplication method:

Multiply 11 11 by 1 1 (last digit of the second 11), we get 11.
Multiply 11 11 by 10 10 (tens place of the second 11), we get 110.

If we align correctly and add the partial products:

     11
+   110
------------
   121

Step 3: The correct multiplication yields the final result as 121 121 . Upon reviewing the provided choices, the correct answer is choice 4: 121 121 .

Therefore, the solution to the problem is 121 121 .

Answer

121

Exercise #7

36= \sqrt{36}=

Video Solution

Step-by-Step Solution

Let's solve the problem step by step:

  • Step 1: Understand what the square root means.
  • The square root of a number nn is a value that, when multiplied by itself, equals nn. This is written as x=nx = \sqrt{n}.

  • Step 2: Apply this definition to the number 3636.
  • We are looking for a number xx such that x2=36x^2 = 36. This translates to finding x=36x = \sqrt{36}.

  • Step 3: Determine the correct number.
  • We know that 6×6=366 \times 6 = 36. Therefore, the principal square root of 3636 is 66.

Thus, the solution to the problem is 36=6 \sqrt{36} = 6 .

Among the given choices, the correct one is: Choice 1: 66.

Answer

6

Exercise #8

64= \sqrt{64}=

Video Solution

Step-by-Step Solution

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

  • Step 1: Recognize what finding a square root means
  • Step 2: List known perfect squares to identify which one results in 64
  • Step 3: Verify the square root by calculation

Now, let's work through each step:
Step 1: To find the square root of 64, we seek a number that, when multiplied by itself, equals 64.
Step 2: Consider the sequence of perfect squares: 12=1 1^2 = 1 , 22=4 2^2 = 4 , 32=9 3^2 = 9 , 42=16 4^2 = 16 , 52=25 5^2 = 25 , 62=36 6^2 = 36 , 72=49 7^2 = 49 , 82=64 8^2 = 64 .
Step 3: We see that 82=64 8^2 = 64 . Therefore, the square root of 64 is 8.

Therefore, the solution to this problem is 8 8 .

Answer

8

Exercise #9

Which of the following clauses is equal to 100?

Video Solution

Step-by-Step Solution

To determine which expression equals 100, we need to evaluate each option:

  • Option 1: 5255^2\cdot5
    - Calculate 52=255^2 = 25.
    - Then compute 255=12525 \cdot 5 = 125.
  • Option 2: 4244^2\cdot4
    - Calculate 42=164^2 = 16.
    - Then compute 164=6416 \cdot 4 = 64.
  • Option 3: 25425^4
    - Calculate (254)(25^4), which simplified through breakdown is larger than 100 because 252=62525^2 = 625. Hence this 25 to the power of 4 will definitely be much larger than 100.
  • Option 4: 52225^2\cdot2^2
    - Calculate 52=255^2 = 25.
    - Calculate 22=42^2 = 4.
    - Compute 254=10025 \cdot 4 = 100.

Therefore, the expression in Option 4, 52225^2\cdot2^2, equals 100. Thus, the correct choice is 4.

Thus, the clause that equals 100 is 52225^2\cdot2^2.

Answer

5222 5^2\cdot2^2

Exercise #10

Which of the following represents the expression below?

15151515 \frac{1}{5}\cdot\frac{1}{5}\cdot\frac{1}{5}\cdot\frac{1}{5} ?

Video Solution

Step-by-Step Solution

To solve the problem, let's represent the repeated multiplication using exponents:

We start with the given expression:

15151515\frac{1}{5} \cdot \frac{1}{5} \cdot \frac{1}{5} \cdot \frac{1}{5}

Notice that 15\frac{1}{5} is multiplied by itself four times. This can be expressed as a power:

(15)4(\frac{1}{5})^4

Hence, the correct representation of the given expression is (15)4(\frac{1}{5})^4.

From the given choices, the correct option is Choice 4: (15)4(\frac{1}{5})^4.

Therefore, the solution to the problem is (15)4 (\frac{1}{5})^4 .

Answer

(15)4 (\frac{1}{5})^4

Exercise #11

Find the value of n:

6n=666 6^n=6\cdot6\cdot6 ?

Video Solution

Step-by-Step Solution

We use the formula: a×a=a2 a\times a=a^2

In the formula, we see that the power shows the number of terms that are multiplied, that is, two times

Since in the exercise we multiply 6 three times, it means that we have 3 terms.

Therefore, the power, which is n in this case, will be 3.

Answer

n=3 n=3

Exercise #12

What is the answer to the following?

3233 3^2-3^3

Video Solution

Step-by-Step Solution

Remember that according to the order of operations, exponents come before multiplication and division, which come before addition and subtraction (and parentheses always before everything),

So first calculate the values of the terms in the power and then subtract between the results:

3233=927=18 3^2-3^3 =9-27=-18 Therefore, the correct answer is option A.

Answer

18 -18

Exercise #13

Sovle:

32+33 3^2+3^3

Video Solution

Step-by-Step Solution

Remember that according to the order of operations, exponents precede multiplication and division, which precede addition and subtraction (and parentheses always precede everything).

So first calculate the values of the terms in the power and then subtract between the results:

32+33=9+27=36 3^2+3^3 =9+27=36 Therefore, the correct answer is option B.

Answer

36

Exercise #14

Solve the following exercise:

x2= \sqrt{x^2}=

Video Solution

Step-by-Step Solution

In order to simplify the given expression, we will use two laws of exponents:

a. The definition of root as an exponent:

an=a1n \sqrt[n]{a}=a^{\frac{1}{n}} b. The law of exponents for power of a power:

(am)n=amn (a^m)^n=a^{m\cdot n}

Let's start with converting the square root to an exponent using the law mentioned in a':

x2=(x2)12= \sqrt{x^2}= \\ \downarrow\\ (x^2)^{\frac{1}{2}}= We'll continue using the law of exponents mentioned in b' and perform the exponent operation on the term in parentheses:

(x2)12=x212x1=x (x^2)^{\frac{1}{2}}= \\ x^{2\cdot\frac{1}{2}}\\ x^1=\\ \boxed{x} Therefore, the correct answer is answer a'.

Answer

x x

Exercise #15

441= \sqrt{441}=

Video Solution

Step-by-Step Solution

The root of 441 is 21.

21×21= 21\times21=

21×20+21= 21\times20+21=

420+21=441 420+21=441

Answer

21 21