Which link between two elements could you remove from the relation so that it becomes a function?

a) 2 and d or 5 and d
b) 2 and d or 3 and b
c) 3 and b or 3 and e
d) 3 and b or 4 and b

Which is the equation of an ellipse with directrices at x = ±4 and foci at (2, 0) and (−2, 0)?

The following graph shows the consumer price index (cpi) for a fictional country from 1970 to 1980? a.) 1976 - 1978b.) 1972 - 1974c.) 1974 - 1976d.) 1978 - 1980

Using pert, adam munson was able to determine that the expected project completion time for the construction of a pleasure yacht is 21 months, and the project variance is 4. a) what is the probability that the project will be completed in 17 months? b) what is the probability that the project will be completed in 20 months? c) what is the probability that the project will be completed in 23 months? d) what is the probability that the project will be completed in 25 months? e) what is the due date that yields a 95% chance of completion?