Question

Express (x + 9)2 as a trinomial in standard form.

Answer 1

`{x}^(2) + 18x + 81`

Explanation:

`(x + 9) {}^(2)`

Apply foil method.

`(x + 9) {}^(2) = (x + 9)(x + 9)`

Multiply the first terms, X

`x * x = {x}^(2)`

Multiply outer terms, 9 and x.

`x * 9 = 9x`

Multiply inner terms,

`9 * x = 9x`

Multiply outer terms.

`9 * 9 = 81`

Add the inner and outer terms

`9x + 9x = 18x`

Write in standard form

`{x}^(2) + 18x + 81`

Answer 2

Explanation: