Question

\(y=3(x+2)(x+6)\)

Short answer

The expanded form of the equation \(y = 3(x + 2)(x + 6)\) is \(y = 3x^2 + 18x + 36\).

Step-by-step solution

Distributing '3' to '(x+2)'

Firstly, distribute '3' to each part inside the parenthesis '(x + 2)', resulting in \(3x+6\).

Distributing the result to '(x+6)'

Now, distribute the result '\(3x+6\)' to each component of the parenthesis '\(x+6\)' individually. This gives the expression \(3x^2+18x+36\).

Key concepts

Polynomial Multiplication

Polynomial multiplication is a fundamental concept in algebra that involves combining polynomials to produce a new polynomial. It is analogous to the multiplication that one performs with numbers, but instead it operates on expressions containing variables and coefficients.

Consider the exercise at hand, which entails multiplying the binomial expressions \(x+2\) and \(x+6\), with an additional coefficient of 3. The process begins by distributing the coefficient to the first binomial, following the distributive property, which states that \(a(b+c) = ab + ac\). Thus, multiplying 3 by \(x+2\) gives us \(3x+6\).

Next, we use the distributive property again, this time to multiply the trinomial \(3x+6\) by the binomial \(x+6\). This involves multiplying each term in the first polynomial by each term in the second polynomial, combing like terms, and simplifying the result to arrive at the quadratic expression \(3x^2+18x+36\).

Quadratic Expressions

Quadratic expressions are polynomials of degree two, commonly written in the standard form \(ax^2 + bx + c\), where \(a\), \(b\), and \(c\) are constants, and \(a \eq 0\). They represent parabolic graphs when plotted on a coordinate axis and are foundational in understanding various real-world phenomena including projectile motion and economics.

When we multiply the polynomials in our exercise, the end result is the quadratic expression \(3x^2+18x+36\). The coefficient \(a=3\) indicates how 'wide' or 'narrow' the associated parabola is, and because it is positive, we know the parabola opens upwards. The expression can be further analyzed or factored if required, and is the foundation for solving quadratic equations through various methods like factoring, completing the square, or using the quadratic formula.

Algebraic Operations

Algebraic operations, including addition, subtraction, multiplication, and division, are performed on algebraic expressions that contain variables, constants, and exponents. In the context of the given problem, we utilize the operation of multiplication across binomials using the distributive property.

This algebraic operation is vital when dealing with expressions and equations in algebra. It enables us to simplify complex expressions, solve equations, and understand the relationships between variables. By mastering operations such as the one demonstrated in our exercise, students can tackle a wide range of algebraic problems, from simplifying expressions to solving intricate equations.