Simplifying Radical Expressions

Simplifying Radical Expressions

Grade 9th Grade · Math · 40 min· Illustrative Mathematics

What's Included

Learning Objective

I can simplify radical expressions.

Reading Passage

Simplifying Radical Expressions

Simplifying radical expressions is a core skill in Algebra 1, allowing us to write them in their most concise form. A radical expression contains a root, most commonly a square root. Our goal when simplifying is to extract any perfect square factors from under the radical sign, leaving the smallest possible integer inside.

The square root symbol denotes the principal (positive) square root. To simplify, we identify perfect square factors within the radicand – the number or expression under the radical. Perfect squares are numbers like 4, 9, 16, and 25, which result from squaring an integer.

The product property of radicals is essential: √(ab) = √a * √b. This property allows us to simplify a radical by rewriting the radicand as a product of a perfect square and another number.

For instance, to simplify √50, we find its largest perfect square factor. Since 25 is a perfect square (5²) and 50 = 25 * 2, we rewrite √50 as √(25 * 2). Applying the product property, this becomes √25 * √2. As √25 equals 5, the simplified form of √50 is 5√2. This method ensures no perfect square factors remain under the radical, making the expression fully simplified for further algebraic work.

Warm-Up Video

Khan Academy · 2:49

Simplifying Radical Expressions 2

Guided Notes

3 key concepts

  • 1

    To simplify 3 times the square root of 200x³, first factor 200 into 2 times 100 and x³ into x² times x.

  • 2

    The square root of 100 simplifies to 10, and the square root of x² simplifies to x.

  • 3

    The simplified expression combines the terms outside the radical to get 30x, and the remaining terms under the radical combine to form √2x.

Practice Questions

9 questions · Multiple choice & Short answer

Exit Ticket

Quick comprehension check

Simplify the radical expression 5√48a³. Show all steps.

Complete Lesson Package

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