Identify the expression to rationalize: \(\frac{7}{\sqrt{5} - 2}\), where the denominator contains a radical.
To rationalize the denominator, multiply both the numerator and the denominator by the conjugate of the denominator. The conjugate of \(\sqrt{5} - 2\) is \(\sqrt{5} + 2\).
Set up the multiplication: \(\frac{7}{\sqrt{5} - 2} \times \frac{\sqrt{5} + 2}{\sqrt{5} + 2}\).
Multiply the numerators: \$7 \times (\sqrt{5} + 2)\(, and multiply the denominators using the difference of squares formula: \)(\sqrt{5})^2 - (2)^2$.
Simplify the denominator to \$5 - 4\(, and write the expression as \)\frac{7(\sqrt{5} + 2)}{1}$, which completes the rationalization process.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Rationalizing the Denominator
Rationalizing the denominator involves eliminating any irrational numbers, such as square roots, from the denominator of a fraction. This is done to simplify the expression and make it easier to work with or interpret.
The conjugate of a binomial expression a + b is a - b, and vice versa. Multiplying a binomial by its conjugate results in a difference of squares, which helps eliminate square roots in the denominator.
The difference of squares formula states that (a + b)(a - b) = a² - b². This property is used when multiplying by the conjugate to remove radicals from the denominator by turning it into a rational number.