Torie00 Torie00
  • 02-07-2022
  • Mathematics
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The square of the difference between a number and 7 is 81 . Find the​ number(s).

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Leora03
Leora03 Leora03
  • 02-07-2022

Answer:

16 or -2

Step-by-step explanation:

Let the number be x.

Difference between the number and 7

= x -7 or 7-x

The square of the difference between x and 7

= (x -7)²

(x -7)²= 81

Square root both sides:

[tex]x - 7= \pm \sqrt{81} [/tex]

[tex]x - 7 = \pm9[/tex]

Add 7 to both sides:

[tex]x = 7\pm9[/tex]

x= 16 or x= -2

Thus, the number could either be 16 or -2.

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