1. The problem is to calculate the value of $$\sqrt{5,2+7}-\sqrt{5,2-7}$$. 2. First, note that the commas in the numbers likely represent decimal points or are a formatting error. Assuming the problem means $$\sqrt{5.2+7}-\sqrt{5.2-7}$$, we simplify inside the radicals: $$5.2 + 7 = 12.2$$ $$5.2 - 7 = -1.8$$ 3. Since the square root of a negative number is not a real number, $$\sqrt{5.2-7} = \sqrt{-1.8}$$ is not real. This suggests a possible typo or misinterpretation. 4. If the problem intended $$\sqrt{5+2\times7} - \sqrt{5+2-7}$$ or similar, please clarify. 5. However, if we interpret the problem as $$\sqrt{5+2+7} - \sqrt{5+2-7} = \sqrt{14} - \sqrt{0} = \sqrt{14} - 0 = \sqrt{14}$$, which is approximately 3.74, not matching any options. 6. Given the options, the closest is 2, 1, 3, or 4. Without clarification, the problem cannot be solved exactly. Therefore, please verify the problem statement for accurate calculation.