Question

How do you find the product `(x-4)(x-9)`?

Answer 1

`x^2 - 13x + 36`

Explanation:

To find the product of these two terms you need to take each term within the parenthesis on the left and multiply it by each term within the parenthesis on the right:

`(color(red)(x - 4))(color(blue)(x - 9)) ->`

`(color(red)(x))(color(blue)(x)) - (color(red)(x))(color(blue)(9)) - (color(red)(4))(color(blue)(x)) + (color(red)(4))(color(blue)(9)) ->`

`x^2 - 9x - 4x + 36`

We can now combine like terms:

`x^2 - (9 + 4)x + 36`

`x^2 - 13x + 36`