Answer key
Name _______________________________
Solve each problem below. Be sure to check each answer to see if you have any extraneous solutions.
Write your solution set in brackets.  
1)
2 7
y
 
7 8 20
2)
x3 1

x2 5
17 
 
4
 325 


14


3)
2
3
x
 
x2 x x2
4)
2
2x  1
1
 2

x  4 x  2x  8 x  2
3
3
5) A biologist introduces 100 insects into a culture. The population P of the culture can be approximated
by the following model where t is the time in hours.
P
500(1  3t )
5t
Find the time requires for the population to increase to 1000 insects.
t= 9
6.5 x
, where
100  x
y is the cost in thousands of dollars of removing x percent of a certain pollutant. Find the cost of
removing 95 percent of pollutants.
6) Suppose a cost-benefit for removing pollutants from the environment is given by y 
.06 thousands
7) Find the vertical asymptotes of the following functions.
3x  7
a)
2x  8
x=4
1
b) 2
x 9
x=3 and x=-3
x 2  2x  1
c) 2
x  4x  3
x=-3 and x=-1
Review for Quiz:
Simplify:
7)
9
4a

10a 5b
8)
9)
x5
x7

2 x  6 4 x  12
10)
11)
3x  3
x 1
 2
x  2x  1 x  1
2
x2 x3

x 1 x 1
1
1 a

4a  4a  1 1  2a
2
x
3
x
x
6
x
12)
1 1

13) a b
1 1

a b