Pearson Algebra 1 Common Core, 2011
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Pearson Algebra 1 Common Core, 2011 View details
Chapter Review
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Exercise 29 Page 654

Use the Multiplication and Division Properties of Square Roots to rewrite 4sqrt(2s) three different ways.

Example Expressions: sqrt(32s), 2sqrt(8s), 8ssqrt(2s)
What They Have in Common: s and a factor of 2 under the radical

Practice makes perfect

We are asked to write three different radical expressions that have 4sqrt(2s) as their simplified form. In order to do this, let's rewrite the given expression in three different ways using the Properties of Square Roots.

First Expression

First, we can rewrite the given expression by moving 4 under the square root. To do this, we need to determine a square root of what number gives us 4. sqrt(16)=4 Now that we know this, we can replace 4 with sqrt(16). Then, using the Multiplication Property of Square Roots, we can rewrite the product as one square root.

Multiplication Property of Square Roots

For a≥ 0 and b≥ 0 sqrt(ab)=sqrt(a)* sqrt(b).

Let's do this!
4sqrt(2s)
sqrt(16)* sqrt(2s)
sqrt(16* 2s)
sqrt(32s)
We can conclude that sqrt(32s) simplifies to 4sqrt(2s).

Second Expression

We can form the second expression in a similar way. However, in this case, we will not rewrite 4, but one of its factors, 2. We can use the fact that 2 is equal to sqrt(4). 4= 2* 2 = 2* sqrt(4) Next, we will apply the Multiplication Property of Square Roots again to combine the two roots.
4sqrt(2s)
2sqrt(4)* sqrt(2s)
2sqrt(4* 2s)
2sqrt(8s)
Therefore, another expression that can be simplified to 4sqrt(2s) is 2sqrt(8s).

Third Expression

Finally, let's form one more expression. Note that if s is not equal to 0, the radicand 2s can be rewritten as 4s^22s. 2s*2s/2s=4s^2/2s Then, we can apply the Division Property of Square Roots.

Division Property of Square Roots

For a≥ 0 and b≥ 0, sqrt(a/b)=sqrt(a)/sqrt(b).

Let's do it!
4sqrt(2s)
4sqrt(4s^2/2s)
4sqrt(4s^2)/sqrt(2s)
42s/sqrt(2s)
8s/sqrt(2s)
A third expression with a simplified form of 4sqrt(2s) is 8ssqrt(2s).

Comparison

Let's now compare all three of our newly created expressions. sqrt(32s), 2sqrt(8s), 8s/sqrt(2s) What do they have in common? Each of these expressions has a square root and they all have s and a factor of 2 under the radical. sqrt(16* 2s), 2sqrt(4* 2s), 8s/sqrt(2s)