3. Rationalize the denominators of the following irrational numbers.

(a) [tex]\frac{3}{\sqrt{3}}[/tex]

(b) [tex]\frac{4}{\sqrt{5}}[/tex]

(c) [tex]\frac{3}{2 \sqrt{3}}[/tex]

(d) [tex]\frac{3 \sqrt{5}}{2 \sqrt{7}}[/tex]



Answer :

Sure, let's rationalize the denominators step by step for each given problem.

### Part (a): [tex]\(\frac{3}{\sqrt{3}}\)[/tex]

To rationalize the denominator, we multiply both the numerator and the denominator by [tex]\(\sqrt{3}\)[/tex]:
[tex]\[ \frac{3}{\sqrt{3}} \times \frac{\sqrt{3}}{\sqrt{3}} = \frac{3 \cdot \sqrt{3}}{\sqrt{3} \cdot \sqrt{3}} = \frac{3 \sqrt{3}}{3} \][/tex]

Simplifying the fraction:
[tex]\[ \frac{3 \sqrt{3}}{3} = \sqrt{3} \][/tex]

So, [tex]\(\frac{3}{\sqrt{3}} = \sqrt{3}\)[/tex].

### Part (b): [tex]\(\frac{4}{\sqrt{5}}\)[/tex]

To rationalize the denominator, we multiply both the numerator and the denominator by [tex]\(\sqrt{5}\)[/tex]:
[tex]\[ \frac{4}{\sqrt{5}} \times \frac{\sqrt{5}}{\sqrt{5}} = \frac{4 \cdot \sqrt{5}}{\sqrt{5} \cdot \sqrt{5}} = \frac{4 \sqrt{5}}{5} \][/tex]

So, [tex]\(\frac{4}{\sqrt{5}} = \frac{4 \sqrt{5}}{5}\)[/tex].

### Part (c): [tex]\(\frac{3}{2 \sqrt{3}}\)[/tex]

To rationalize the denominator, we multiply both the numerator and the denominator by [tex]\(\sqrt{3}\)[/tex]:
[tex]\[ \frac{3}{2 \sqrt{3}} \times \frac{\sqrt{3}}{\sqrt{3}} = \frac{3 \cdot \sqrt{3}}{2 \sqrt{3} \cdot \sqrt{3}} = \frac{3 \sqrt{3}}{2 \cdot 3} \][/tex]

Simplifying the fraction:
[tex]\[ \frac{3 \sqrt{3}}{6} = \frac{\sqrt{3}}{2} \][/tex]

So, [tex]\(\frac{3}{2 \sqrt{3}} = \frac{\sqrt{3}}{2}\)[/tex].

### Part (d): [tex]\(\frac{3 \sqrt{5}}{2 \sqrt{7}}\)[/tex]

To rationalize the denominator, we multiply both the numerator and the denominator by [tex]\(\sqrt{7}\)[/tex]:
[tex]\[ \frac{3 \sqrt{5}}{2 \sqrt{7}} \times \frac{\sqrt{7}}{\sqrt{7}} = \frac{3 \sqrt{5} \cdot \sqrt{7}}{2 \sqrt{7} \cdot \sqrt{7}} = \frac{3 \sqrt{35}}{2 \cdot 7} \][/tex]

Simplifying the fraction:
[tex]\[ \frac{3 \sqrt{35}}{14} \][/tex]

So, [tex]\(\frac{3 \sqrt{5}}{2 \sqrt{7}} = \frac{3 \sqrt{35}}{14}\)[/tex].