Final answer:
Cannot determine the correct expression for DA without additional context or the relevant information regarding the pattern or rules of the sequence.
Step-by-step explanation:
The question asks for the correct expression to find the value of DA, and it seems to be related to some sequence or pattern given in the problem statement. Without the proper context or pattern, it's not possible to determine which of the provided options a. DA = 24x + 35, b. DA = 35 - x, c. DA = 35x + 2, or d. DA = 47x + 47 is the correct formula to calculate DA. Typically such a question would be part of a sequence or based on some rule that has been determined in a prior part of the exercise, which isn't provided here. To provide the correct formula for DA, more information or additional parts of the question would be necessary. However, based on the information given about quadratic equations and the value of 'x', it is not possible to accurately determine which formula to use for calculating DA.