Which expression is the factorization of x^2 + 10x + 21
a(x + 3)(x + 7)
b(x + 4)(x + 6)
c(x + 6)(x + 15)
d(x + 7)(x + 14)

A

Explanation: The factorization of any equation of the form x^2+bx+c will equal (x+p)(x+q) if p+q=b and p*q=c. We want the equation in which p+q=10 (b) and pq=21(c). The answer is A since 7+3 equals 10 and 7*3 equals 21

the answer to the question is a  

it has the same slope and the same y-intercept.

the first one, all those points on the line just make a strait line.