A school student did a project on solar energy for a competition. For demo, the lights are set up along a straight line and have charging points at \(A \left(\frac{-7}{3}, 0 \right)\), \(B \left(0, \frac{7}{4} \right)\), \(C(3, 4)\), \(D(7, 7)\) and \(E(x, y)\). Find the distance between \(C(3, 4)\) and \(D(7, 7)\) and \(E(x, y)\). Also, the distance between \(C\) and \(E\) is \(10\) units.
Based on the above information, answer the following questions.
1. Find the distance \(CD\).
2. Calculate the distance \(DE\).
3. The value of \(x + y\) is
4. Which of the following is true?