Question

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(x+9)(x-9) Polynomial identities

Answer 1

The given expression is simplified as
`(x + 9)(x -9)  = x^(2)   - 81`

Explanation:

Here,the given expression is (x+9)(x -9)

Using the ALGEBRAIC IDENTITY:

`(a +b)(a -b)  = a^2  - b^2`

Now, here in the given expression (x + 9)(x -9)

Comparing it the left side of the identity,

we get a = x

and b = 9

The right side of the equation is
`a^(2)   - b^(2)`

Substituting the value of a and b, we get

⇒
`(x + 9)(x -9)  =   (x)^(2)   - (9)^(2)`

=
`x^(2)   - 81`

Hence, the given expression is simplified as
`(x + 9)(x -9)  = x^(2)   - 81`