Elementary and Intermediate Algebra: Concepts & Applications (6th Edition)

Published by Pearson
ISBN 10: 0-32184-874-8
ISBN 13: 978-0-32184-874-1

Chapter 5 - Polynomials and Factoring - 5.2 Factoring Trinomials of the Type x2+bx+c - 5.2 Exercise Set - Page 317: 16

Answer

$(a-4)(a-5)$

Work Step by Step

The 2 numbers whose product is $ac= 1(20)=20 $ and whose sum is $b= -9 $ are $\left\{ -4,-5 \right\}.$ Using these two numbers to decompose the middle term of the given trinomial, $ a^2-9a+20 ,$ then the factored form is \begin{array}{l} a^2-4a-5a+20 \\\\= (a^2-4a)-(5a-20) \\\\= a(a-4)-5(a-4) \\\\= (a-4)(a-5) .\end{array}
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.