Given the relation A = {(3,5), (4,9), (7,2), (x,6)}, which of the following values for x will make the relation A a function? 7, 4, 3, 5

The answer is 5.

Domain cannot be repetitive. We already have 3,4 and 7 so these numbers cannot be used repetitive for domain. Therefore, 5 is the answer here.

none of the above.

for one of the equations to be used in the process, there has to be a term in the equation since squared is .

since there is only a term in the first equation, we cannot derive a from completing the square.

solving with completing the square