Question

Which expression is the factorization of x2 + 10x + 21?

Answer 1

You must remember that a polynomial is written like so...

ax^2 + bx + c

In this case...

a = 1

b = 10

c = 21

To factor you must find two numbers who both add up to b (10) AND multiply to c (21)

3 + 7 = 10

3 * 7 = 21

so...

(x + 3 )(x + 7)

Hope this helped!

~Just a girl in love with Shawn Mendes

Answer 2

Answer: 12x + 21  or  C. F(x) = (x - 2)(x + 2)

Step-by-step explanation:

x2 + 10x + 21

2x + 10x + 21  

Rearrange to put the coefficient in front/move it in front of the term.

Ex. (× · 4 ⇒ 4×)

     (×( 7 ) ⇒ 7×)

Identify  and group like terms.

 (2x + 10x) + 21

Group the coefficients together.

 (2+ 10)x + 21

Combine 2 + 10 to get 12.

 12x + 21

= 12x + 21

You're Welcome! :))