How do you factor the expressions x2+7x18?

3 Answers
May 12, 2018

(x+9)(x2)

Explanation:

Given: x2+7x18.

Split the middle term.

x2+9x2x18.

Factor by each side.

x(x+9)2(x+9).

(x+9)(x2)

May 12, 2018

(x+9)(x2)

Explanation:

since the coefficient of the x2 term is 1 then

the factors of - 18 which sum to + 7 are + 9 and - 2

x2+7x18=(x+9)(x2)

May 12, 2018

(x+9)(x2)

Explanation:

With this type of quadratic, we need to find a number that adds to make 7, but multiplies to make 18:

We can start by listing the factors of 18:

18and1

1and18

9and2

2and9

6and3

3and6

9+(2)=7 therefore this combination will work

Place in double brackets:

(x+9)(x2)

We can check by expanding:

(x+9)(x2)=x22x+9x18

x2+7x18