The ordered pairs (2, –21) and (5, –45) are solutions to which of the following equations?

a. (x, y) -> (x - 4, y - 2)
b. (x, y) -> (x + 4, y - 2)
c. (x, y) -> (x + 4, y + 2)
d. (x, y) -> (x - 4, y + 2)

pls

If a || b and b | y, then ? a) x || y. b) x | a. c) a | y. d) a || y.

Evaluate the discriminant of each equation. tell how many solutions each equation has and whether the solutions are real or imaginary. 4x^2 + 20x + 25 = 0

Carl's candies has determined that a candy bar measuring 3 inches long has a z-score of +1 and a candy bar measuring 3.75 inches long has a z-score of +2. what is the standard deviation of the length of candy bars produced at carl's candies?