If the domain of the square root function f(x) is x < _7, which statement must be true?

a) 7 is subtracted from the x-term inside the radical.
b) the radical is multiplied by a negative number.
c) 7 is added to the radical term. d) the x-term inside the radical has a negative coefficient.

plz hurry timed quiz

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?