Math Problem Statement

Simplify 5√2/(√10 - √5) - 3√5/(√5 - √2) - √10/(√2 - 1)

Solution

The given expression to simplify is:

5210535521021\frac{5\sqrt{2}}{\sqrt{10} - \sqrt{5}} - \frac{3\sqrt{5}}{\sqrt{5} - \sqrt{2}} - \frac{\sqrt{10}}{\sqrt{2} - 1}

To simplify this, we will rationalize each denominator and work through the terms step by step. Let me start by simplifying the terms.

Step 1: Rationalize the first term

52105\frac{5\sqrt{2}}{\sqrt{10} - \sqrt{5}}

We multiply both the numerator and the denominator by the conjugate of the denominator: 52(105)(10+5)(10+5)=52(10+5)(10)2(5)2\frac{5\sqrt{2}}{(\sqrt{10} - \sqrt{5})} \cdot \frac{(\sqrt{10} + \sqrt{5})}{(\sqrt{10} + \sqrt{5})} = \frac{5\sqrt{2}(\sqrt{10} + \sqrt{5})}{(\sqrt{10})^2 - (\sqrt{5})^2}

Simplifying the denominator: (10)2(5)2=105=5(\sqrt{10})^2 - (\sqrt{5})^2 = 10 - 5 = 5

Now, simplify the numerator: 52(10+5)=520+510=105+5105\sqrt{2}(\sqrt{10} + \sqrt{5}) = 5\sqrt{20} + 5\sqrt{10} = 10\sqrt{5} + 5\sqrt{10}

Thus, the first term becomes: 105+5105=25+10\frac{10\sqrt{5} + 5\sqrt{10}}{5} = 2\sqrt{5} + \sqrt{10}

Step 2: Rationalize the second term

3552\frac{3\sqrt{5}}{\sqrt{5} - \sqrt{2}}

Multiply by the conjugate of the denominator: 35(52)(5+2)(5+2)=35(5+2)(5)2(2)2\frac{3\sqrt{5}}{(\sqrt{5} - \sqrt{2})} \cdot \frac{(\sqrt{5} + \sqrt{2})}{(\sqrt{5} + \sqrt{2})} = \frac{3\sqrt{5}(\sqrt{5} + \sqrt{2})}{(\sqrt{5})^2 - (\sqrt{2})^2}

Simplifying the denominator: (5)2(2)2=52=3(\sqrt{5})^2 - (\sqrt{2})^2 = 5 - 2 = 3

Simplify the numerator: 35(5+2)=3×5+310=15+3103\sqrt{5}(\sqrt{5} + \sqrt{2}) = 3 \times 5 + 3\sqrt{10} = 15 + 3\sqrt{10}

Thus, the second term becomes: 15+3103=5+10\frac{15 + 3\sqrt{10}}{3} = 5 + \sqrt{10}

Step 3: Rationalize the third term

1021\frac{\sqrt{10}}{\sqrt{2} - 1}

Multiply by the conjugate of the denominator: 10(21)(2+1)(2+1)=10(2+1)(2)2(1)2\frac{\sqrt{10}}{(\sqrt{2} - 1)} \cdot \frac{(\sqrt{2} + 1)}{(\sqrt{2} + 1)} = \frac{\sqrt{10}(\sqrt{2} + 1)}{(\sqrt{2})^2 - (1)^2}

Simplifying the denominator: (2)212=21=1(\sqrt{2})^2 - 1^2 = 2 - 1 = 1

Thus, the third term becomes: 10(2+1)=20+10=25+10\sqrt{10}(\sqrt{2} + 1) = \sqrt{20} + \sqrt{10} = 2\sqrt{5} + \sqrt{10}

Final Expression

Now, summing up all three terms: (25+10)(5+10)(25+10)(2\sqrt{5} + \sqrt{10}) - (5 + \sqrt{10}) - (2\sqrt{5} + \sqrt{10})

Simplifying the expression: 25+1051025102\sqrt{5} + \sqrt{10} - 5 - \sqrt{10} - 2\sqrt{5} - \sqrt{10}

The terms 252\sqrt{5} and 25-2\sqrt{5} cancel out, and 101010\sqrt{10} - \sqrt{10} - \sqrt{10} simplifies to 10-\sqrt{10}. So we are left with: 510-5 - \sqrt{10}

Thus, the simplified expression is: 510\boxed{-5 - \sqrt{10}}

Would you like more details or clarifications on any part of the process?

Relative Questions:

  1. How do you rationalize a denominator involving square roots?
  2. What are conjugates, and how do they help simplify expressions?
  3. Why do the terms cancel out in the final step of simplification?
  4. How does squaring square roots help in rationalizing denominators?
  5. Can this method be applied to more complex radical expressions?

Tip: Always simplify square roots and perform factorization if possible before combining terms to make the process easier.

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Math Problem Analysis

Mathematical Concepts

Radicals
Algebraic Simplification
Rationalization

Formulas

(a - b)(a + b) = a² - b²
Rationalizing the denominator

Theorems

Rationalization using conjugates
Difference of squares

Suitable Grade Level

Grades 9-12