Math Problem Statement

3/(sqrt(2)-2)-2/(sqrt(2)+1)=

Solution

To solve the given expression, we need to simplify the expression by rationalizing the denominators. Here is the step-by-step solution:

32222+1\frac{3}{\sqrt{2} - 2} - \frac{2}{\sqrt{2} + 1}

Step 1: Rationalize the Denominators

For 322\frac{3}{\sqrt{2} - 2}:

Multiply the numerator and the denominator by the conjugate of the denominator, 2+2\sqrt{2} + 2:

322×2+22+2=3(2+2)(22)(2+2)\frac{3}{\sqrt{2} - 2} \times \frac{\sqrt{2} + 2}{\sqrt{2} + 2} = \frac{3(\sqrt{2} + 2)}{(\sqrt{2} - 2)(\sqrt{2} + 2)}

Simplify the denominator:

(22)(2+2)=(2)2(2)2=24=2(\sqrt{2} - 2)(\sqrt{2} + 2) = (\sqrt{2})^2 - (2)^2 = 2 - 4 = -2

So:

3(2+2)2=32+62=3223\frac{3(\sqrt{2} + 2)}{-2} = \frac{3\sqrt{2} + 6}{-2} = -\frac{3\sqrt{2}}{2} - 3

For 22+1\frac{2}{\sqrt{2} + 1}:

Multiply the numerator and the denominator by the conjugate of the denominator, 21\sqrt{2} - 1:

22+1×2121=2(21)(2+1)(21)\frac{2}{\sqrt{2} + 1} \times \frac{\sqrt{2} - 1}{\sqrt{2} - 1} = \frac{2(\sqrt{2} - 1)}{(\sqrt{2} + 1)(\sqrt{2} - 1)}

Simplify the denominator:

(2+1)(21)=(2)2(1)2=21=1(\sqrt{2} + 1)(\sqrt{2} - 1) = (\sqrt{2})^2 - (1)^2 = 2 - 1 = 1

So:

2(21)1=222\frac{2(\sqrt{2} - 1)}{1} = 2\sqrt{2} - 2

Step 2: Combine the Two Expressions

Now we combine the two simplified expressions:

3223(222)-\frac{3\sqrt{2}}{2} - 3 - (2\sqrt{2} - 2)

Distribute the negative sign and combine like terms:

322322+2-\frac{3\sqrt{2}}{2} - 3 - 2\sqrt{2} + 2

Convert 222\sqrt{2} to a common denominator:

22=4222\sqrt{2} = \frac{4\sqrt{2}}{2}

Combine like terms:

3224223+2=7221-\frac{3\sqrt{2}}{2} - \frac{4\sqrt{2}}{2} - 3 + 2 = -\frac{7\sqrt{2}}{2} - 1

So, the simplified expression is:

7221-\frac{7\sqrt{2}}{2} - 1

Would you like more details or have any questions about this solution? Here are five questions you might ask next:

  1. How do you rationalize the denominator of a fraction?
  2. Can you explain the process of multiplying by the conjugate in more detail?
  3. How do you simplify expressions involving square roots?
  4. Why is it necessary to combine like terms in algebraic expressions?
  5. Can you show another example of simplifying a similar expression?

Tip: When dealing with square roots and fractions, rationalizing the denominator can often simplify the problem significantly.

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Math Problem Analysis

Mathematical Concepts

Algebra
Rationalization
Simplification of Expressions

Formulas

Rationalizing the denominator
Combining like terms

Theorems

Conjugate multiplication

Suitable Grade Level

Grades 10-12