Add or subtract as indicated.
10. 11.
Simplify each complex fraction.
12. 13. 14.
15.Identify each of the following as an expression to be simplified or an equation to be
solved. Then simplify the expression and solve the equation.
(a) (b)
Solve each equation.
18.Solve for the variable in this formula from mathematics:
19.Graph the function defined by Give the equations of its vertical and hori-
zontal asymptotes.
Solve each problem.
20.Chris Dada can do a job in 9 hr, while Dana Bortes can do the same job in 5 hr. How long
would it take them to do the job if they worked together?
21.The rate of the current in a stream is 3 mph. Nana’s boat can go 36 mi downstream in the
same time that it takes to go 24 mi upstream. Find the rate of her boat in still water.
22.Biologists collected a sample of 600 fish from West Okoboji Lake on May 1 and tagged
each of them. When they returned on June 1, a new sample of 800 fish was collected and
10 of these had been previously tagged. Use this experiment to determine the approximate
fish population of West Okoboji Lake.
23.In biology, the function defined by
gives the growth rate of a population for xunits of available food. (Source:Smith, J. Maynard,
Models in Ecology,Cambridge University Press.)
(a)What amount of food (in appropriate units) would produce a growth rate of 3 units of
growth per unit of food?
(b)What is the growth rate if no food is available?
24.The current in a simple electrical circuit is inversely proportional to the resistance. If the
current is 80 amps when the resistance is 30 ohms, find the current when the resistance is
12 ohms.
25.The force of the wind blowing on a vertical surface varies jointly as the area of the surface
and the square of the velocity. If a wind blowing at 40 mph exerts a force of 50 lb on a sur-
face of 500 ft^2 , how much force will a wind of 80 mph place on a surface of 2 ft^2?
g 1 x 2 =
5 x
2 +x
ƒ 1 x 2 =x-+^21.
S=
n
2
/ 1 a+/ 2.
y
y+ 2
-
1
y- 2
=
8
y^2 - 4
1
x
-
4
3 x
=
1
x- 2
2 x
3
+
x
4
=
11
2
2 x
3
+
x
4
-
11
2
2 x-^2 +y-^2
x-^1 - y-^1
1
a
1
b
a
b
12
r+ 4
11
6 r+ 24
6
x+ 4
+
1
x+ 2
-
3 x
x^2 + 6 x+ 8
9
x^2 - 6 x+ 9
+
2
x^2 - 9
3
7 a^4 b^3
+
5
21 a^5 b^2
7
6 t^2
-
1
3 t
424 CHAPTER 7 Rational Expressions and Functions
