1. The problem is to find the rationalizing factor for an expression involving a radical. 2. The rationalizing factor is used to eliminate the square root or radical from the denominator or numerator of a fraction. 3. For example, if you have an expression like $\frac{1}{\sqrt{a}}$, the rationalizing factor is $\sqrt{a}$ because multiplying numerator and denominator by $\sqrt{a}$ removes the radical from the denominator. 4. If the expression is $\frac{1}{a + \sqrt{b}}$, the rationalizing factor is the conjugate $a - \sqrt{b}$. 5. Multiplying numerator and denominator by the conjugate uses the difference of squares formula: $$(a + \sqrt{b})(a - \sqrt{b}) = a^2 - (\sqrt{b})^2 = a^2 - b$$ 6. This eliminates the radical in the denominator. 7. To find the rationalizing factor, identify the radical part and use either the radical itself or its conjugate depending on the expression. 8. No video can be provided here, but these steps explain how to find the rationalizing factor clearly.