Question

1. $r^2 + 3r - 28$; $(r + 7)(r - 4)$ 0/1 pt

Explanation:

Step1: Identify $a,b,c$ for quadratic

For $r^2+3r-28$, $a=1, b=3, c=-28$

Step2: Find factor pair of $ac$

$ac=1\times(-28)=-28$, find pair: $7$ and $-4$ (since $7+(-4)=3=b$)

Step3: Split middle term and factor

$r^2+7r-4r-28 = r(r+7)-4(r+7)=(r+7)(r-4)$

Answer:

$(r + 7)(r - 4)$