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

(x + 3)(x + 7)

Step-by-step explanation:

Given

x² + 10x + 21

Consider the factors of the constant term (+ 21) which sum to give the coefficient of the x- term (+ 10)

The factors are + 3 and + 7, since

3 × 7 = 21 and 3 + 7 = 10, hence

x² + 10x + 21 = (x + 3)(x + 7)

f(2x−x2)=−3x2+6x−1

step-by-step explanation:

set up the composite function and evaluate.

f(2x−x2)=−3x2+6x−1