Tính: (8 + 2√2)/(3 - √2) - (2 + 3√2)/(√2 + √2)/(1 - √2) f) (8 + 2sqrt(2))/(3 - sqrt(2)) - (2 + 3sqrt(2))/(sqrt(2)) + (sqrt(2))/(1 - sqrt(2))
Tham khảo câu trả lời từ Trợ lý ảo Lazi To simplify this expression, we need to rationalize the denominators. First, let's rationalize the denominator of the first fraction, (8 + 2sqrt(2))/(3 - sqrt(2)): Multiply the numerator and denominator by the conjugate of the denominator, which is (3 + sqrt(2)): [(8 + 2sqrt(2))/(3 - sqrt(2))] * [(3 + sqrt(2))/(3 + sqrt(2))] = ([(8 + 2sqrt(2))(3 + sqrt(2)]) / [(3 - sqrt(2))(3 + sqrt(2))]) Expanding the numerator and denominator: = [(24 + 8sqrt(2) + 6sqrt(2) + 2 * sqrt(2)^2) / (9 - 2)] = [(24 + 14sqrt(2) + 2 * 2) / 7] = (28 + 14sqrt(2)) / 7 = 4 + 2sqrt(2) Now, let's rationalize the denominator of the second fraction, (2 + 3sqrt(2))/(sqrt(2)): Multiply the numerator and denominator by sqrt(2): [(2 + 3sqrt(2))/(sqrt(2))] * [(sqrt(2))/(sqrt(2))] = [(2sqrt(2) + 3sqrt(2) * sqrt(2)) / (sqrt(2) * sqrt(2))] Simplifying: = [(2sqrt(2) + 3sqrt(2)^2) / 2] = [(2sqrt(2) + 3 * 2) / 2] = (2sqrt(2) + 6) / 2 = sqrt(2) + 3 Finally, let's rationalize the denominator of the third fraction, (sqrt(2))/(1 - sqrt(2)): Multiply the numerator and denominator by the conjugate of the denominator, which is (1 + sqrt(2)): [(sqrt(2))/(1 - sqrt(2))] * [(1 + sqrt(2))/(1 + sqrt(2))] = [(sqrt(2))(1 + sqrt(2)) / (1 - sqrt(2))(1 + sqrt(2))] Expanding the numerator and denominator: = [(sqrt(2) + sqrt(2)^2) / (1 - sqrt(2) + sqrt(2) - sqrt(2)^2)] = [(sqrt(2) + 2) / (1 - 2)] = (sqrt(2) + 2) / -1 = -sqrt(2) - 2 Now, we can substitute these simplified fractions back into the original expression: (4 + 2sqrt(2)) - (sqrt(2) + 3) + (-sqrt(2) - 2) Combining like terms: = 4 + 2sqrt(2) - sqrt(2) - 3 - sqrt(2) - 2 = 4 - 3 - 2 + 2sqrt(2) - sqrt(2) - sqrt(2) = -1 - sqrt(2)