Corrections to problems in
Modeling, Functions, and Graphs – Algebra for College Students
by Franklin/Drooyan
Ch 1 Review: #49 form of answer is not expanded. It should be:
a  b  2 a 2  2ab  b 2  2a  2b  4
Section 2.5: #89 exact answer is 8.415789  10 2


Ch 2 Review: #55 Some books have y  1 in the denominator of problem instead of y 1
Section 3.1: #73
175 is between 13 and 14, not 12 and 13.
Section 3.2 #89 the exponent of –1/2 should be –1.2 instead
Section 3.4: #13 answer has
4
x 2 in it which simplifies to
x
Section 4.1 #69 answer should be 293 hours
3 , 3 ,1,1
Section 4.5 #57 some books don’t have all solutions:
Cumulative Review of Part 1: #34 answer should be
y y 3
2( y  3)
Section 5.1 #3(b) answer should be 52
Section 5.4 #21 book used the points  4,20 and 6,60 to get estimate
#27(d) answer is parallel, not perpendicular
Ch 5 Review: #30 answer is 5 x  2 y  16
Section 6.5 #25 vertex isn’t graphed high enough
Ch 6 Review #18 in some books they write “2” as “z”. it should be “2”
#31 to get answer in back of book, change problem to:
 x3 , if x  1
S ( x)  
 x, if x  1
Section 7.1 #3 shape of the graph is a bit funky
3
#43 answer should be: y   x  3  1
Section 7.2 #13 first answer is  6.2928 and second answer is 142.4442
Section 7.3 #9 graph should look like:
Section 7.5 #7 answer should be: f 1 ( x)  3  2 x
Ch 7 Review: #20 graph should look like:
#44 problem should say: find G 1 (3)
Section 8.1 #15(b) answer is 46.1 pounds, not 46.7
Section 8.4 #27 answer is about 0.05, not 0.50
Section 8.5 #91 answers are approximately 11.7 years and 11.6 years
Section 9.2 #13 some books have “9”instead of “  9 ” in the third equation:
it should be "9" .
Section 10.3 #25 answer should be (, 316 ]  (4, )
Section 10.4 #7 wrong side of line is shaded – shade other side
#35 lines are incorrect – region is a quadrilateral with
vertices (0,1), (0,3) ( 332 ,25) and (5,2)
5
  181 , 
Chapter 10 Review #24 answer should be:  , 18
Section 11.1 #23 the center is mislabeled – it should be 0,3
Section 12.4 #61 answer is 9/20, not 9/4