Question

Factorise \(144 \alpha^{2}-49 \beta^{2}\)

Short answer

Answer: The factorised form of the expression is \((12\alpha+7\beta)(12\alpha-7\beta)\).

Step-by-step solution

Identify the squares

The given expression is \(144\alpha^{2}-49\beta^{2}\). We can identify \(144\alpha^{2}\) as \((12\alpha)^2\) and \(49\beta^{2}\) as \((7\beta)^2\).

Apply the Difference of Squares formula

Using the formula \(a^2 - b^2 = (a + b)(a - b)\), we can rewrite the expression as \((12\alpha+7\beta)(12\alpha-7\beta)\).

Write the final factorised form

The factorised form of the given expression is \((12\alpha+7\beta)(12\alpha-7\beta)\).

Key concepts

Algebraic Identities

One of the fundamental tools in simplifying algebraic expressions is utilizing well-known algebraic identities. An algebraic identity is an equation that holds true for all values of its variables. A common example, and highly relevant to our exercise, is the Difference of Squares identity which is expressed as \( a^2 - b^2 = (a + b)(a - b) \).

This identity is particularly useful because it allows us to factorise expressions that look like the difference between two perfect squares. Recognizing this pattern is essential when approaching problems that require factorisation. Moreover, by mastering algebraic identities like this, students can solve complex equations more easily and streamline the process of simplifying expressions.

It's important to memorize algebraic identities as they are the building blocks for more advanced algebra and are frequently encountered in various mathematical problems.

Polynomial Factorisation

Moving on to the concept of polynomial factorisation, which is the process of expressing a polynomial as a product of its factors. Factors are polynomials that multiply together to give the original polynomial. Factorisation is not only a crucial step in solving polynomial equations but also in simplifying algebraic expressions and finding zeros of polynomials.

In the case of our exercise, we deal with a special form of polynomial known as a quadratic binomial. This is because it has two terms and the highest exponent is two. The factored form reveals the roots of the polynomial, which are the values of the variable that make the polynomial equal to zero. For the expression \(144\beta^{2} - 49\beta^{2}\), we identified and factored it using an algebraic identity specifically designed for differences of squares, showcasing a direct application of polynomial factorisation.

Quadratic Equations

Finally, understanding how to approach quadratic equations is crucial for students. A quadratic equation is a second-degree polynomial equation in a single variable, usually expressed in the form \( ax^2 + bx + c = 0 \), where \( a \), \( b \), and \( c \) are coefficients and \( a \) is not equal to zero.

The exercise we have tackled doesn't present a quadratic equation in the standard form, but it relates closely to the concept. Had we set the expression \(144\beta^{2} - 49\beta^{2} = 0\), solving it would involve factoring the quadratic binomial and finding the values of \(\alpha\) and \(\beta\) that satisfy the equation. This is an essential method in finding the solutions to quadratic equations and is intricately linked to the process of factorising polynomials.

Moreover, the ability to factorise quadratic equations is an invaluable skill in mathematics, as it not only applies to algebra but also to calculus and other areas of advanced mathematics.