Respuesta :

Let's set up the variables for the two numbers --> 'a' , 'b'

Now let's set up some equations based on the given information:

  • sum of two numbers is 6 --> a + b = 6
  • sum of their squares is 90 --> a^2 + b^2 = 90

Equations:

  • a + b = 6 -- equation 1
  • a^2 + b^2 = 90 -- equation 2

   Solve (equation 1) for b in terms of a

     b = a - 6 -- equation 3

 

    (equation 3) into (equation 2)

     a^2 + (a - 6)^2 = 90

     a^2 + a^2 - 12a + 36 = 90

     2a^2 - 12a - 54 = 0

     (2a + 6)(a - 9) = 0

       a = -3 -- equation 4

       a = 9 -- equation 5

    (equation 4) into (equation 1)

      -3 + b = 6

       b = 9  - ---   a = -3, b= 9

    (equation 5) into ( equation 1)

     9 + b = 6

     b = -3 - ---     a = 9, b= -3

Since the numbers are interchangeable, the two numbers are -3 and 9.

Hope it helps!