How do you factor the trinomial $x^2-x-42$ ?

Question

How do you factor the trinomial $x^2-x-42$ ?

2 Answers

Impact of this question

4401 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2018-07-05T15:07:13

$(x-7)(x+6)$

Explanation:

$"the factors of "-42" which sum to "-1$
$"are "-7" and "+6$

$x^2-x-42=(x-7)(x+6)$

Answer 2 · 2018-07-05T15:29:21

$(x-7)(x+6)$

Explanation:

Given: $x^2-x-42$ .

With some $color(blue)(bb(magic))$ , notice how it equals:

$=x^2-7x+6x-42$

$=x(x-7)+6(x-7)$

$=(x-7)(x+6)$

The $color(blue)(bb(magic))$ is that you pick two numbers, say $a$ and $b$ , whose sum equals the coefficient of the middle term and whose product equals the last terms.

In other words, we get:

$ab=-42$

$a+b=-1$

Clearly, $-7$ and $6$ are the numbers.

Science

Math

Humanities

... and beyond

How do you factor the trinomial $x^2-x-42$ ?

2 Answers

Explanation:

Explanation:

Related questions

Impact of this question

Science

Math

Humanities

... and beyond

How do you factor the trinomial x^2-x-42 x^2-x-42?

2 Answers

Explanation:

Explanation:

Related questions

Impact of this question

How do you factor the trinomial $x^2-x-42$ ?