Question

How do you multiply `(a-7)(a-3)`?

Answer 1

See the entire solution process below:

Explanation:

To multiply these two terms together you multiply each of the terms within the left parenthesis by each of the terms in the right parenthesis:

`(color(red)(a) - color(red)(7))(color(blue)(a) - color(blue)(3))` becomes:

`(color(red)(a) xx color(blue)(a)) - (color(red)(a) xx color(blue)(3)) - (color(red)(7) xx color(blue)(a)) + (color(red)(7) xx color(blue)(3))`

`a^2 - 3a - 7a + 21`

Now, combine like terms:

`a^2 + (-3 - 7)a + 21`

`a^2 - 10a + 21`