How do you factorize $8{x^2} + 18x + 9$?
Answer
624.6k+ views
Hint: Given polynomial is of degree 2. Polynomials of degree 2 are known as Quadratic polynomials. Quadratic polynomials can be factored by the help of splitting the middle term method. In this method, the middle term is split into two terms in such a way that the polynomial remains unchanged.
Complete step by step answer:
For factorising the given quadratic polynomial $8{x^2} + 18x + 9$, we can use the splitting method in which the middle term is split into two terms such that the sum of the terms gives us the original middle term and product of the terms gives us the product of the constant term and coefficient of ${x^2}$.
So, $8{x^2} + 18x + 9$
$ \Rightarrow 8{x^2} + (12 + 6)x + 9$
We split the middle term $18x$ into two terms $12x$ and $6x$ since the product of these terms, $72{x^2}$ is equal to the product of the constant term and coefficient of ${x^2}$ and sum of these terms gives us the original middle term, $18x$.
$ \Rightarrow 8{x^2} + 12x + 6x + 9$
$ \Rightarrow 4x(2x + 3) + 3(2x + 3)$
$ \Rightarrow (4x + 3)(2x + 3)$
So, the factored form of the quadratic polynomial $\left( {8{x^2} + 18x + 9} \right)$ is $(4x + 3)(2x + 3)$.
Additional Information: Similar to quadratic polynomials, quadratic solutions can also be solved using factorisation method. Besides factorisation, there are various methods to solve quadratic equations such as completing the square method and using the Quadratic formula.
Note: Splitting of the middle term can be a tedious process at times when the product of the constant term and coefficient of ${x^2}$ is a large number with a large number of divisors. Special care should be taken in such cases.
Complete step by step answer:
For factorising the given quadratic polynomial $8{x^2} + 18x + 9$, we can use the splitting method in which the middle term is split into two terms such that the sum of the terms gives us the original middle term and product of the terms gives us the product of the constant term and coefficient of ${x^2}$.
So, $8{x^2} + 18x + 9$
$ \Rightarrow 8{x^2} + (12 + 6)x + 9$
We split the middle term $18x$ into two terms $12x$ and $6x$ since the product of these terms, $72{x^2}$ is equal to the product of the constant term and coefficient of ${x^2}$ and sum of these terms gives us the original middle term, $18x$.
$ \Rightarrow 8{x^2} + 12x + 6x + 9$
$ \Rightarrow 4x(2x + 3) + 3(2x + 3)$
$ \Rightarrow (4x + 3)(2x + 3)$
So, the factored form of the quadratic polynomial $\left( {8{x^2} + 18x + 9} \right)$ is $(4x + 3)(2x + 3)$.
Additional Information: Similar to quadratic polynomials, quadratic solutions can also be solved using factorisation method. Besides factorisation, there are various methods to solve quadratic equations such as completing the square method and using the Quadratic formula.
Note: Splitting of the middle term can be a tedious process at times when the product of the constant term and coefficient of ${x^2}$ is a large number with a large number of divisors. Special care should be taken in such cases.
Recently Updated Pages
What are the two major island groups in India class 9 social science CBSE

What is Jhum cultivation class 9 biology CBSE

Write an Article on Save Earth Save Life

Silk is obtained from of the silk moth APupa BLarva class 9 chemistry CBSE

Write chemical formulas of the following compounds class 9 chemistry CBSE

The Indo Gangetic Plains of India are fertile due to class 9 social science CBSE

Trending doubts
Fill the blanks with the suitable prepositions 1 The class 9 english CBSE

Difference Between Plant Cell and Animal Cell

What is the full form of pH?

On an outline map of India show its neighbouring c class 9 social science CBSE

What is pollution? How many types of pollution? Define it

Differentiate between parenchyma collenchyma and sclerenchyma class 9 biology CBSE


