Question

How do you find the product `(11-a)^2`?

Answer 1

`color(brown)(a^2-22a+121`

Explanation:

`color(white)(aaaaaaaaaaaa)` `11-a`
`color(white)(aaaaaaaaaa)` `underline( xx 11-a)`
`color(white)(aaaaaaaaaaaaa)` `121-11a`
`color(white)(aaaaaaaaaaaaaaaaa)` `underline(-11a+a^2)`
`color(white)(aaaaaaaaaaaaaa)` `121-22a+a^2`
`color(white)(aaaaaaaaaaaaaa)` `color(brown)(a^2-22a+121`

Answer 2

`121-22a+a^2`

Explanation:

`"express " (11-a)^2=(11-a)(11-a)`

Each term in the second bracket is multiplied by each term in the first bracket as shown below.

`(color(red)(11-a))(11-a)`

`=color(red)(11)(11-a)color(red)(-a)(11-a)`

`=(color(red)(11)xx11)+(color(red)(11)xx-a)+(color(red)(-a)xx11)+(color(red)(-a)xx-a)`

`=121-11a-11a+a^2`

`=121-22a+a^2`