#### Answer

100

#### Work Step by Step

The coefficient of x is 20.
Adding the square of half the coefficient creates a perfect square.
$(20\div2)^2=10^2=100$

Published by
Pearson

ISBN 10:
0-13417-805-X

ISBN 13:
978-0-13417-805-9

100

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

Update this answerAfter 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.