Question

How do you factor the expression `9x^2 - 4`?

Answer 1

`(3x-2)(3x+2)`

Explanation:

Given: `9x^2-4`

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This is very similar to `(a^2-b^2)` which can be factored into
`(a-b)(a+b)`. So if we can change `9x^2-4` into the standard form of `(a^2-b^2)` we have our solution.

Consider `9x^2`
This can be written as `(3x)^2`

Consider 4
This can be written as `2^2`
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Write as `(3x)^2-2^2` when factored this becomes:

`(3x-2)(3x+2)`