Which values of x and y would make the following expression represent a real number? (4 + 5i)(x + yi)
x = 4, y = 5
x = –4, y = 0
x = 4, y = –5
x = 0, y = 5

Aquality characteristic of new iphone x made at the amsterdam plant at apple computers has a manufacturing specification (in mm) of 0.200 +/- .07. historical data indicates that if the quality characteristic takes on values greater than 0.27 or smaller than 0.13 the component fails at a cost of20.19. based on these data: determine the taguchi loss function (must show work) calculate an estimated loss for a quality characteristic of .30 calculate an estimated loss for quality characteristic of .40.