contestada

Find the number if the square root of another number that is 6 greater than this number is equal to the number itself.

Respuesta :

Answer:

  3

Step-by-step explanation:

Let x represent the number of interest. Then x+6 is "another number". You want its square root to be the original number:

  √(x+6) = x

Squaring both sides, we get ...

  x +6 = x^2

In standard form, this is ...

  x^2 -x -6 = 0

  (x -3)(x +2) = 0 . . . . factored

By the zero product rule, this will have solutions ...

  x -3 = 0  ⇒  x = 3

  x +2 = 0  ⇒  x = -2 . . . . . an extraneous solution, because √(-2+6) ≠ -2

The number is 3.