Extracting the common factor in parentheses - Examples, Exercises and Solutions

Understanding Extracting the common factor in parentheses

Complete explanation with examples

Common Factor Extraction Method:
Identify the largest free number that we can extract.
Then, let's move on to the variables and ask what is the least number of times the X X appears in any element?
Multiply the free number by the variable the same number of times we have found and we will obtain the greatest common factor.

To verify that you have correctly extracted the common factor, open the parentheses and see if you have returned to the original exercise.

Detailed explanation

Practice Extracting the common factor in parentheses

Test your knowledge with 7 quizzes

Solve for x:

\( 7x^5-14x^4=0 \)

Examples with solutions for Extracting the common factor in parentheses

Step-by-step solutions included
Exercise #1

Solve the following problem:

x2x=0 x^2-x=0

Step-by-Step Solution

Shown below is the given equation:

x2x=0 x^2-x=0

First note that on the left side we are able to factor the expression using a common factor. The largest common factor for the numbers and letters in this case is x x and this is due to the fact that the first power is the lowest power in the equation. Therefore it is included both in the term with the second power and in the term with the first power. Any power higher than this is not included in the term with the first power, which is the lowest. Hence this is the term with the highest power that can be factored out as a common factor from all terms in the expression. Continue to factor the expression:

x2x=0x(x1)=0 x^2-x=0 \\ \downarrow\\ x(x-1)=0

Proceed to the left side of the equation that we obtained in the last step. There is a multiplication of algebraic expressions and on the right side the number 0. Therefore given that the only way to obtain 0 from a multiplication is to multiply by 0, at least one of the expressions in the multiplication on the left side must equal zero,

Meaning:

x=0 \boxed{x=0}

or:

x1=0x=1 x-1=0\\ \downarrow\\ \boxed{x=1}

Let's summarize then the solution to the equation:

x2x=0x(x1)=0x=0x=0x1=0x=1x=0,1 x^2-x=0 \\ \downarrow\\ x(x-1)=0 \\ \downarrow\\ x=0 \rightarrow\boxed{ x=0}\\ x-1=0 \rightarrow \boxed{x=1}\\ \downarrow\\ \boxed{x=0,1}

Therefore the correct answer is answer B.

Answer:

x=0,1 x=0,1

Video Solution
Exercise #2

x4+2x2=0 x^4+2x^2=0

Step-by-Step Solution

To solve the equation x4+2x2=0x^4 + 2x^2 = 0, we will use the technique of factoring. Let's proceed step-by-step:

First, notice that both terms x4x^4 and 2x22x^2 have a common factor of x2x^2. We can factor x2x^2 out from the equation:

x2(x2+2)=0x^2(x^2 + 2) = 0

Now, to solve for xx, we apply the Zero Product Property, which gives us that at least one of the factors must be zero:

  • x2=0x^2 = 0 or
  • x2+2=0x^2 + 2 = 0

Solving the first case, x2=0x^2 = 0:

x=0x = 0

For the second case, x2+2=0x^2 + 2 = 0, we reach:

x2=2x^2 = -2

Since x2=2x^2 = -2 has no real solutions (squares of real numbers are non-negative), we can conclude that this equation doesn't provide additional real solutions.

Therefore, the only real solution to the given equation is x=0x = 0.

The correct choice from the provided options is:

x=0 x=0

Answer:

x=0 x=0

Video Solution
Exercise #3

Solve the following equation:

7x1014x9=0 7x^{10}-14x^9=0

Step-by-Step Solution

Shown below is the given equation:

7x1014x9=0 7x^{10}-14x^9=0

First, note that on the left side we are able to factor the expression using a common factor.

The largest common factor for the numbers and variables in this case is 7x9 7x^9 given that the ninth power is the lowest power in the equation and therefore is included in both the term with the tenth power and the term with the ninth power. Any power higher than this is not included in the term with the ninth power, which is the lowest, and therefore this is the term with the highest power that can be factored out as a common factor from all terms for the variables,

For the numbers, note that 14 is a multiple of 7, therefore 7 is the largest common factor for the numbers in both terms of the expression,

Let's continue and perform the factoring:

7x1014x9=07x9(x2)=0 7x^{10}-14x^9=0 \\ \downarrow\\ 7x^9(x-2)=0

On the left side of the equation that we obtained in the last step there is a multiplication of algebraic expressions and on the right side the number 0, therefore, since the only way to obtain a result of 0 from a multiplication operation is to multiply by 0, at least one of the expressions in the multiplication on the left side must equal zero,

Meaning:

7x9=0/:7x9=0/9x=0 7x^9=0 \hspace{8pt}\text{/}:7\\ x^9=0 \hspace{8pt}\text{/}\sqrt[9]{\hspace{6pt}}\\ \boxed{x=0}

In solving the equation above, we first divided both sides of the equation by the term with the variable, and then we proceeded to extract a ninth root from both sides of the equation.

(In this case, extracting an odd root from the right side of the equation yielded one possibility)

Or:

x2=0x=2 x-2=0 \\ \boxed{x=2}

Let's summarize the solution of the equation:

7x1014x9=07x9(x2)=07x9=0x=0x2=0x=2x=0,2 7x^{10}-14x^9=0 \\ \downarrow\\ 7x^9(x-2)=0\\ \downarrow\\ 7x^9=0 \rightarrow\boxed{ x=0}\\ x-2=0\rightarrow \boxed{x=2}\\ \downarrow\\ \boxed{x=0,2}

Therefore, the correct answer is answer A.

Answer:

x=2,x=0 x=2,x=0

Video Solution
Exercise #4

Solve the following problem:

x6+x5=0 x^6+x^5=0

Step-by-Step Solution

Shown below is the given equation:

x6+x5=0 x^6+x^5=0

First, note that on the left side we are able to factor the expression by using a common factor.

The largest common factor for the numbers and variables in this case is x5 x^5 given that the fifth power is the lowest power in the equation and therefore is included both in the term with the sixth power and in the term with the fifth power. Any power higher than this is not included in the term with the fifth power, which is the lowest, and therefore this is the term with the highest power that can be factored out as a common factor from all terms in the expression. Proceed with the factoring of the expression:

x6+x5=0x5(x+1)=0 x^6+x^5=0 \\ \downarrow\\ x^5(x+1)=0

Let's continue to the left side of the equation that we obtained in the last step. There is a multiplication of algebraic expressions and on the right side the number 0. Therefore, due to the fact that the only way to obtain 0 from a multiplication is to multiply by 0, at least one of the expressions in the multiplication on the left side must equal zero,

meaning:

x5=0/5x=0 x^5=0 \hspace{8pt}\text{/}\sqrt[5]{\hspace{6pt}}\\ \boxed{x=0} (in this case taking the odd root of the right side of the equation will yield one possibility)

or:

x+1=0x=1 x+1=0\\ \boxed{x=-1}

Let's summarize the solution of the equation:

x6+x5=0x5(x+1)=0x5=0x=0x+1=0x=1x=0,1 x^6+x^5=0 \\ \downarrow\\ x^5(x+1)=0 \\ \downarrow\\ x^5=0 \rightarrow\boxed{ x=0}\\ x+1=0 \rightarrow \boxed{x=-1}\\ \downarrow\\ \boxed{x=0,-1}

Therefore the correct answer is answer A.

Answer:

x=1,x=0 x=-1,x=0

Video Solution
Exercise #5

Solve the following problem:

3x2+9x=0 3x^2+9x=0

Step-by-Step Solution

Shown below is the given problem:

3x2+9x=0 3x^2+9x=0

First, note that in the left side we are able to factor the expression by using a common factor. The largest common factor for the numbers and letters in this case is 3x 3x due to the fact that the first power is the lowest power in the equation and therefore is included both in the term with the second power and in the term with the first power. Any power higher than this is not included in the term with the first power, which is the lowest. Therefore this is the term with the highest power that can be factored out as a common factor from all terms for the letters,

For the numbers, note that 9 is a multiple of 3, therefore it is the largest common factor for the numbers in both terms of the expression,

Let's continue to factor the expression:

3x2+9x=03x(x+3)=0 3x^2+9x=0 \\ \downarrow\\ 3x(x+3)=0

Proceed to the left side of the equation that we obtained in the last step. There is a multiplication of algebraic expressions and on the right side the number 0. Therefore, given that the only way to obtain 0 from a multiplication is to multiply by 0, at least one of the expressions in the multiplication on the left side must equal zero,

Meaning:

3x=0/:3x=0 3x=0 \hspace{8pt}\text{/}:3\\ \boxed{x=0}

In solving the above equation, we divided both sides of the equation by the term with the variable,

Or:

x+3=0x=3 x+3=0 \\ \boxed{x=-3}

Let's summarize the solution of the equation:

3x2+9x=03x(x+3)=03x=0x=0x+3=0x=3x=0,3 3x^2+9x=0 \\ \downarrow\\ 3x(x+3)=0 \\ \downarrow\\ 3x=0 \rightarrow\boxed{ x=0}\\ x+3=0\rightarrow \boxed{x=-3}\\ \downarrow\\ \boxed{x=0,-3}

Therefore the correct answer is answer C.

Answer:

x=0,x=3 x=0,x=-3

Video Solution

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