√ (18 - 8 * √ 2) - √ (3 - 2 * √ 2) = √ (16 - 2 * 4 * √ 2 + 2) - √ (2 - 2 * √ 2 + 1) =
√ (4 - √ 2)² - √ (√ 2 - 1)² = 4 - √ 2 - (√ 2 - 1) = 5 - 2 * √ 2
√ (18 - 8 * √ 2) - √ (3 - 2 * √ 2) = √ (16 - 2 * 4 * √ 2 + 2) - √ (2 - 2 * √ 2 + 1) =
√ (4 - √ 2)² - √ (√ 2 - 1)² = 4 - √ 2 - (√ 2 - 1) = 5 - 2 * √ 2