The sum of two numbers is 11, and their difference is 9. what are the two numbers?

  10 and 1

Step-by-step explanation:

Let x and y represent the two numbers. The problem statement lets us write two equations describing their relationships:

  x + y = 11

  x - y = 9

Adding these equations together, we have ...

  (x +y) +(x -y) = (11) +(9)

  2x = 20

  x = 10 . . . . . . . . . you will notice this is the average of the two given numbers

Then ...

  10 + y = 11 . . . . substitute for x in the first equation

  y = 1 . . . . . . . subtract 10

The two numbers are 10 and 1.

{3 + i, 3 - i, 3, -1}

step-by-step explanation:

step-by-step explanation: it is d