Radical Expressions

11-7Multiplying, Dividing, and Simplifying Radicals

Overview

√a · √b = √(ab); √a / √b = √(a/b). Simplify by extracting perfect squares.

Key ideas

  • Combine under one radical, then simplify.
  • Rationalize a denominator by multiplying by √(same) / √(same).
  • Reduce final radicand.

Worked examples

Example 1

Problem. √3 · √12

Solution. √36 = 6

Example 2

Problem. Rationalize 1/√2.

Solution. √2/2

Practice

Try each one. Click Show answer when ready.

  1. 1.

    √5 · √20

  2. 2.

    Simplify √(45).

  3. 3.

    Rationalize 3/√3.

Challenge problems

A little tougher — great for test prep. Click Show answer when ready.

  1. 1.

    Simplify √12 · √27.

  2. 2.

    Simplify (√50)/(√2).