Question

What identity can be used to rewrite the expression 4x^2-9

Answer 1

You cannot factor it, so there is no simplification. The Constants "4" and "9" do not share a common factor, therefore, you cannot simplify it. However, if it was a number such as "8" replacing "9", then you can simplify by doing:

4(x^2 - 2) = 4x^2-9

Answer 2

[(2x)² - 3²] = (2x-3) (2x+3)

Explanation:

The given expression is ( 4x² - 9)

We have to tell the identity to factorize the given expression.

We can rewrite the expression as [ (2x)² - 3² ]

To factor if we will use the identity

[a² - b² = (a-b) (a+b) ]

so expression will become

[(2x)² - 3²] = (2x-3) (2x+3)