## College Algebra (10th Edition)

C. $ab = C$ and $a+b=B$
If $x^2+Bx+C=(x+a)(x+b),$ then the answer is C: $ab = C$ and $a+b=B$ To prove this, we can use the FOIL method for the terms in the problem: $(x+a)(x+b)=$ $x^2+xb+xa+ab$ Therefore, seeing that ab is the last term, we know it corresponds with C, and seeing that the sum of xb and xa is the second term, then $a+b$ corresponds with the B term.