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Ch. R - Algebra Review
Lial - Trigonometry 12th Edition
Lial12th EditionTrigonometryISBN: 9780136552161Not the one you use?Change textbook
Chapter 1, Problem 10

CONCEPT PREVIEW Perform the operations mentally, and write the answers without doing intermediate steps. (√28 - √14) (√28 + √14)

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1
Recognize that the expression \((\sqrt{28} - \sqrt{14})(\sqrt{28} + \sqrt{14})\) is in the form of a difference of squares: \((a - b)(a + b) = a^2 - b^2\).
Identify \(a = \sqrt{28}\) and \(b = \sqrt{14}\) in the given expression.
Apply the difference of squares formula: \(a^2 - b^2 = (\sqrt{28})^2 - (\sqrt{14})^2\).
Simplify the squares of the square roots: \((\sqrt{28})^2 = 28\) and \((\sqrt{14})^2 = 14\).
Subtract the results to get the simplified expression: \(28 - 14\).

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Difference of Squares Formula

The difference of squares formula states that (a - b)(a + b) = a² - b². This identity allows simplification of expressions involving the product of conjugates without expanding each term individually.
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