Question

Which expression is the factorization of x2 + 10x + 21? (x + 3)(x + 7) (x + 4)(x + 6) (x + 6)(x + 15) (x + 7)(x + 14)

Answer 1

A: (x + 3)(x + 7)

Explanation:

Answer 2

Answer: First option.

Explanation:

You need to remember that to factorize the given expression
`x^2+10x+21`, you need to choose two numbers that when you add them you get "10" and when you multiply them you get "21".

These number are:

7 and 3

Because:

`7+3=10\\7*3=21`

Therefore, you get that the factorization of the expression
`x^2+10x+21` is the following:

`(x+3)(x+7)`

You can observe that this factorization matches with the first option.