Question

Factor completely. x2 −3x−40 Enter your answer in the box.

Answer 1

`\displaystyle( x - 8)(x + 5)`

Explanation:

we would like to factor the following expression:

`\displaystyle {x}^(2) - 3x - 40`

in order to do so rewrite the middle term as 5x-8x:

`\displaystyle {x}^(2) + 5x - 8x - 40`

factor out x:

`\displaystyle x ({x}^{} + 5) - 8x - 40`

factor out -8:

`\displaystyle x ({x}^{} + 5) - 8(x + 5)`

group:

`\displaystyle( x - 8)(x + 5)`

and we are done!

Answer 2

(x - 8) (x + 5)

Explanation:

You want to start with breaking down -40 to find the integers that will go into that, which are 8 and 5. Then you take the knowledge of 8 and 5 and turn your attention to -3x.

8 and 5 must be added together to equal -3x. 8 is the larger number so it must be the negative in the equation and be must be the positive. Thus it would be -8x + 5x = -3x

Knowing that, is it simple to break x^2 because it is simply x * x = x^2