How do you FOIL $(8x^3-7)(x^7-9)$ ?

Question

1525 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2018-03-12T12:43:56

$8x^10-7x^7-72x^3+63$

F - Firsts
O - Outers
I - Inners
L- Lasts

![https://calculator.tutorvista.com/http://foil-calculator.html](https://useruploads.socratic.org/HxVpjg8ARzivoVHTnhLL_foil_method.jpg)

Now, let's get started,

$(8x^3-7)(x^7-9)$

Multiply firsts,

$8x^3xxx^7=8x^10$

Multiply outers,

$8x^3xx-9=-72x^3$

Multiply inners,

$-7xxx^7=-7x^7$

Multiply lasts,

$-7xx-9=63$

Lastly add them all up,

$8x^10-7x^7-72x^3+63$

How do you FOIL (8x^3-7)(x^7-9)(8x^3-7)(x^7-9)?