Solve for X: √2 × √3 = x/√6 Radical Equation

Question

Solve the following equation:

23=x6 \sqrt{2}\cdot\sqrt{3}=\frac{x}{\sqrt{6}}

Video Solution

Solution Steps

00:00 Find X
00:03 When multiplying the square root of a number (A) by the square root of another number (B)
00:06 The result equals the square root of their product (A times B)
00:10 We'll use this formula in our problem and calculate the multiplication
00:18 We'll multiply by the denominator to eliminate the fraction
00:26 We'll use our formula again and calculate the multiplication
00:34 Any number multiplied by itself is essentially squared
00:37 The square root of any number (A) squared cancels out the square
00:40 And this is the solution to the question

Step-by-Step Solution

Introduction:

We will address the following two laws of exponents:

a. Definition of root as an exponent:

an=a1n \sqrt[n]{a}=a^{\frac{1}{n}}

b. The law of exponents for an exponent applied to terms in parentheses:

(ab)n=anbn (a\cdot b)^n=a^n\cdot b^n

Note:

By combining these two laws of exponents mentioned in a (in the first and third steps ahead) and b (in the second step ahead), we can obtain a new rule:

abn=(ab)1n=a1nb1n=anbnabn=anbn \sqrt[n]{a\cdot b}=\\ (a\cdot b)^{\frac{1}{n}}=\\ a^{\frac{1}{n}}\cdot b^{\frac{1}{n}}=\\ \sqrt[n]{a}\cdot \sqrt[n]{ b}\\ \downarrow\\ \boxed{\sqrt[n]{a\cdot b}=\sqrt[n]{a}\cdot \sqrt[n]{ b}}

And specifically for the fourth root we get:

ab=ab \boxed{ \sqrt{a\cdot b}=\sqrt{a}\cdot \sqrt{ b}}

Therefore, we will proceed with solving the problem as follows:

x6=23 \frac{x}{\sqrt{6}} = \sqrt{2}\cdot\sqrt{3}

First, we'll eliminate the fraction line, which we'll do by multiplying both sides of the equation by the common denominator which is- 6 \sqrt{6} :

x6=23/6x=236 \frac{x}{\sqrt{6}} = \sqrt{2}\cdot\sqrt{3} \hspace{6pt}\text{/}\cdot\sqrt{6}\\ x=\sqrt{2}\cdot\sqrt{3}\cdot \sqrt{6}

Let's continue and simplify the expression on the left side of the equation, using the rule we received in the introduction:

ab=ab \boxed{ \sqrt{a\cdot b}=\sqrt{a}\cdot \sqrt{ b}}

(which of course also applies to multiplication between numbers under a root), next we'll perform the multiplication under the root:

x=236x=236x=36x=6 x=\sqrt{2}\cdot\sqrt{3}\cdot\sqrt{6} \\ x=\sqrt{2\cdot3\cdot6} \\ x=\sqrt{36}\\ \boxed{x=6}

In the final step, we used the known fourth root of the number 36,

Let's summarize the solution of the equation:

x6=23/6x=236x=36x=6 \frac{x}{\sqrt{6}} = \sqrt{2}\cdot\sqrt{3} \hspace{6pt}\text{/}\cdot\sqrt{6}\\ x=\sqrt{2}\cdot\sqrt{3}\cdot \sqrt{6} \\ x=\sqrt{36}\\ \boxed{x=6}

Therefore, the correct answer is answer a.

Answer

6