Question

How do you simplify `(x + 9)(x -2)`?

Answer 1

`x^2+7x-18`

Explanation:

Each term in the second bracket must be multiplied by each term in the first bracket. This can be achieved as follows.

`rArr(color(red)(x+9))(x-2)`

`=color(red)(x)(x-2)color(red)(+9)(x-2)`

distribute the brackets.

`=x^2-2x+9x-18`

collect like terms.

`=x^2+(-2+9)x-18`

`=x^2+7x-18`