Question

Please help me and include step by step!!! (x+9)(x-9) Polynomial identities

Answer 1

Answer:

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

Step-by-step 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 $(x + 9)(x -9) = x^{2} - 81$