Question

Find the factors of x2 - 9​

Answer 1

Answer:

One way to solve the quadratic equation x2 = 9 is to subtract 9 from both sides to get one side equal to 0: x2 – 9 = 0. The expression on the left can be factored: (x + 3)(x – 3) = 0. Using the zero factor property, you know this means x + 3 = 0 or x – 3 = 0, so x = −3 or 3.

Answer 2

Given,

$\[{x^2} - 9\]$

Solution,

Calculate the factors.

Know that $\[{a^2} - {b^2} = \left( {a + b} \right)\left( {a - b} \right)\]$

$\[\begin{array}{l} = {x^2} - 9\\ = {x^2} - {3^2}\end{array}\]$

$\[ = \left( {x + 3} \right)\left( {x - 3} \right)\]$

Hence the factors are $\[\left( {x + 3} \right)\left( {x - 3} \right)\]$