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show your solution. (x+9) (x-9)


Sagot :

The solution is x² - 81.

We need to simplify the following expression:

⇒ [tex]\sf (x+9)(x-9)[/tex]

The way we're going to simplify this is we are going to use FOIL.

FOIL is an acronym that stands for:

  • First
  • Outside
  • Inside
  • Last

Now let's simplify.

First multiply all the terms

[tex]\sf x*x + x*(-9)+9*x+9*(-9)[/tex]

Now simplify

[tex]\sf x^2+9x-9x-81[/tex]

Combine the like terms in the middle

[tex]\sf x^2-81[/tex]