Chapter 10: Problem 47
Simplify. Remember to use absolute-value notation when necessary. If a root cannot be simplified, state this. $$ \sqrt{4 x^{2}+28 x+49} $$
Short Answer
Expert verified
|2x + 7|
Step by step solution
01
Identify Polynomial
Identify the polynomial under the square root: \[ \ 4x^2 + 28x + 49 \]
02
Rewrite Polynomial
Rewrite the polynomial in a form that may indicate a perfect square trinomial: \[ \ 4x^2 + 28x + 49 = (2x)^2 + 2 \times 2x \times 7 + 7^2 \]
03
Express as a Square
Recognize that \[ 4x^2 + 28x + 49 = (2x + 7)^2 \]
04
Take the Square Root
Simplify the square root of both sides: \[ \ \sqrt{4x^2 + 28x + 49} = \sqrt{(2x + 7)^2} \]
05
Apply Absolute Value
The square root of a square encompasses absolute value: \[ \ \sqrt{(2x + 7)^2} = |2x + 7| \]
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Key Concepts
These are the key concepts you need to understand to accurately answer the question.
absolute value
The absolute value of a number or expression measures its distance from zero on a number line. This value is always non-negative, irrespective of the original number being positive or negative.
Consider an example: \, |x|. If \(x\) is 3, \(|x| = 3\). Likewise, if \(x\) is -3, then \(|x| = 3\) as well.
Absolute value becomes particularly significant when dealing with expressions under a square root. For example, simplifying \(\sqrt{\left(2x + 7\right)^2}\) results in \(|2x + 7|\). Here, the absolute value ensures the expression remains non-negative.
Remember, when taking the square root of a square, always use absolute value notation: \(\sqrt{a^2} = |a|\).
Consider an example: \, |x|. If \(x\) is 3, \(|x| = 3\). Likewise, if \(x\) is -3, then \(|x| = 3\) as well.
Absolute value becomes particularly significant when dealing with expressions under a square root. For example, simplifying \(\sqrt{\left(2x + 7\right)^2}\) results in \(|2x + 7|\). Here, the absolute value ensures the expression remains non-negative.
Remember, when taking the square root of a square, always use absolute value notation: \(\sqrt{a^2} = |a|\).
perfect square trinomials
A perfect square trinomial is a quadratic expression of the form \(a^2 + 2ab + b^2\), which can be factored into \((a + b)^2\).
Recognizing patterns in the trinomial helps in simplification:
Perfect square trinomials simplify computation involving square roots by organizing complex expressions into more manageable forms.
Always look out for squared terms, cross-products, and constant squares in quadratic expressions to identify perfect square trinomials.
Recognizing patterns in the trinomial helps in simplification:
- Identify terms that are squares: \(4x^2 + 28x + 49\)
- Rewrite as: \((2x)^2 + 2(2x)(7) + 7^2\)
- Recognize this matches the form: \((a+b)^2\)
- Which simplifies to: \((2x + 7)^2\)
Perfect square trinomials simplify computation involving square roots by organizing complex expressions into more manageable forms.
Always look out for squared terms, cross-products, and constant squares in quadratic expressions to identify perfect square trinomials.
polynomial simplification
Polynomial simplification is the process of reducing a polynomial to its simplest form. This involves combining like terms and factoring where possible.
Steps to simplify a polynomial:
It transforms complex expressions into understandable and manageable forms.
Steps to simplify a polynomial:
- Identify all like terms—terms with the same variable raised to the same power.
- Combine like terms.
- Factor the polynomial where possible.
- Identify that it's a perfect square: \((2x + 7)^2\)
- Thus, simplifying it directly to \((2x + 7)^2\)
It transforms complex expressions into understandable and manageable forms.
square root
The square root function, denoted by \(\sqrt{...}\), finds a number that, when multiplied by itself, gives the original number.
For instance, \(\sqrt{9} = 3\) and \(\sqrt{16} = 4\).
When working with expressions under a square root, recognizing perfect square patterns is crucial.
For the expression \(\sqrt{(2x + 7)^2}\):
This allows simpler and clearer solutions in algebra and calculus, promoting better mathematical understanding.
For instance, \(\sqrt{9} = 3\) and \(\sqrt{16} = 4\).
When working with expressions under a square root, recognizing perfect square patterns is crucial.
For the expression \(\sqrt{(2x + 7)^2}\):
- We identify it as a perfect square.
- Taking the square root simplifies it: \(|2x + 7|\).
This allows simpler and clearer solutions in algebra and calculus, promoting better mathematical understanding.