Solve Fifth Root Expression: Multiplying ∛(3³) and ∛(3²)

Question

Solve the following exercise:

335325= \sqrt[5]{3^3}\cdot\sqrt[5]{3^2}=

Video Solution

Solution Steps

00:00 Simplify the following expression
00:03 The C root of the A value to the power of B
00:06 The result will be equal to number A to the power of B divided by C
00:10 We will use this formula in our exercise
00:14 When multiplying powers with equal bases
00:17 The power of the result equals the sum of the powers
00:21 We will use this formula in our exercise, and add the powers
00:36 This is the solution

Step-by-Step Solution

In order to simplify the given expression, we will use two laws of exponents:

a. The root law (expanded):

amn=amn=(an)m \sqrt[\textcolor{blue}{n}]{a^{\textcolor{red}{m}}}=a^{\frac{\textcolor{red}{m}}{\textcolor{blue}{n}}} =(\sqrt[\textcolor{blue}{n}]{a})^{\textcolor{red}{m}}

b. The law of exponents for multiplication between terms with identical bases:

aman=am+n a^m\cdot a^n=a^{m+n}

We'll start by converting the roots to exponent notation using the law of exponents mentioned in a:

335325=335325= \sqrt[\textcolor{blue}{5}]{3^{\textcolor{red}{3}}}\cdot\sqrt[\textcolor{blue}{5}]{3^{\textcolor{red}{2}}}= \\ \downarrow\\ 3^{\frac{\textcolor{red}{3}}{\textcolor{blue}{5}}}\cdot3^{\frac{\textcolor{red}{2}}{\textcolor{blue}{5}}} =

Since we are multiplying two terms with identical bases, we'll use the law of exponents mentioned in b:

335325=335+25= 3^{\frac{3}{5}}\cdot3^{\frac{2}{5}}= \\ 3^{\frac{3}{5}+\frac{2}{5}}=

We'll continue and separately perform the addition of fractions in the exponent of the expression. We'll do this by expanding each of the fractions to the common denominator—the number 5—then we'll perform the multiplication and addition operations in the fraction numerator:

35+25=3+25=55=1 \frac{3}{5}+\frac{2}{5}=\\ \frac{3+2}{5}=\\ \frac{5}{5}=\\ 1

Therefore, we get:

335+25=31=3 3^{\frac{3}{5}+\frac{2}{5}}=\\ 3^{1}=\\ \boxed{3}

Let's summarize the expression simplification process:

335325=335+25=3 \sqrt[5]{3^3}\cdot\sqrt[5]{3^2}= \\ \downarrow\\ 3^{\frac{3}{5}+\frac{2}{5}}=\\ \boxed{3}

Therefore, the correct answer is answer a.

Answer

3 3