Chapter 0: Problem 75
Factor by any method. $$4 z^{2}+28 z+49$$
Short Answer
Expert verified
The expression \(4z^2 + 28z + 49\) factors as \((2z + 7)^2\).
Step by step solution
01
Identify the Form
The given expression is a quadratic trinomial: \(4z^{2} + 28z + 49\). We want to determine if it can be written in the form \((az + b)^2\). This expression resembles a perfect square trinomial.
02
Check the Coefficients
In a perfect square trinomial \((az + b)^2 = a^2z^2 + 2abz + b^2\), the first and last terms should be perfect squares. Here,- First term: \(4z^2 = (2z)^2\)- Last term: \(49 = 7^2\)
03
Verify Middle Term
The middle term in a perfect square trinomial should be \(2abz\), where \(a=2\) and \(b=7\). Calculate:\(2 imes 2 imes 7 = 28\), which matches the middle term of the original expression \(28z\).
04
Write the Expression as a Square
Since all the terms align with the perfect square trinomial pattern, we can write the expression as:\((2z + 7)^2\).
05
Factor the Quadratic
The factorization of \(4z^2 + 28z + 49\) is \((2z + 7)(2z + 7)\) or simply \((2z + 7)^2\).
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Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Perfect Square Trinomial
One powerful technique in factoring quadratics is recognizing a perfect square trinomial, a special type of quadratic expression. A perfect square trinomial is one that can be expressed as the square of a binomial. The general form is \((ax + b)^2 = a^2x^2 + 2abx + b^2\).
For example, consider the trinomial \(4z^2 + 28z + 49\). To determine if it's a perfect square trinomial, identify if both the first and last terms are perfect squares:
Recognizing these patterns makes factoring quicker and simpler, transforming a quadratic into an easily manageable form.
For example, consider the trinomial \(4z^2 + 28z + 49\). To determine if it's a perfect square trinomial, identify if both the first and last terms are perfect squares:
- The first term \(4z^2\) is \((2z)^2\).
- The last term \(49\) is \(7^2\).
Recognizing these patterns makes factoring quicker and simpler, transforming a quadratic into an easily manageable form.
Quadratic Trinomials
Quadratic trinomials are algebraic expressions of the form \(ax^2 + bx + c\), where \(a\), \(b\), and \(c\) are constants. Understanding these forms is crucial as they appear widely in algebraic problems.
In the exercise, \(4z^2 + 28z + 49\), \(a = 4\), \(b = 28\), and \(c = 49\).
Quadratic trinomials appear in various forms; finding effective methods to factor them can simplify problem-solving. Methods include:
In the exercise, \(4z^2 + 28z + 49\), \(a = 4\), \(b = 28\), and \(c = 49\).
Quadratic trinomials appear in various forms; finding effective methods to factor them can simplify problem-solving. Methods include:
- Finding common factors and factoring them out,
- Recognizing patterns like perfect square trinomials,
- Using the quadratic formula when applicable.
Factoring Techniques
Factoring is a strategy used to simplify expressions, solve equations, and scrutinize expression structures. It is particularly useful when working with quadratic equations, allowing for easy solutions.
In our example, the trinomial \(4z^2 + 28z + 49\) is factored by recognizing it as a perfect square trinomial. Factoring techniques vary based on the expression's form.
In our example, the trinomial \(4z^2 + 28z + 49\) is factored by recognizing it as a perfect square trinomial. Factoring techniques vary based on the expression's form.
- Recognize perfect square trinomials, as we did: \((2z + 7)^2\).
- Factor by grouping, which can simplify more complex expressions into two binomials.
- Employ the Distributive Property reversely to write expressions as a product.