Download EXM 3 M80_sp06

Spring 2006
Math 80 Exam 3
Name_____________
150pts Show work for credit
I. Simplify the rational expressions. (a,b 3pts, c=4pts)
 15a 3 b 4 c 2
a)
 25ab12 c 2
c)
BOX ANSWER!
49  n 2
b) 2
n  14n  49
4y2 1
6y4

8y2  6y 1 8y2  2y
II. Find the domain for each function.(3pts each)
a) f ( x) 
3x  1
3
x
5
b) f ( x) 
___________
8
6 x  13x  15
2
________________
c) f ( x) 
5x  2
10
____________
III. Determine the LCD, then add/subtract and simplify.( 5pts each)
a) LCD = _____________________
b) LCD = _______________________
15n 3 11n 3

8m
8m
3x  1
3 x
 2
x  5x  6 x  5x  6
c) LCD = _____________________
d) LCD = ______________________
2
x
2
 2
2x  4 x  2x
3
5
1 
4
3x y
6 xy 2
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6/28/2017
Spring 2006
Math 80 Exam 3
Name_____________
150pts Show work for credit
BOX ANSWER!
IV. Determine the LCD, any restriction(s), then solve.(5pts each)
a) LCD = ___________________
b) LCD = _____________________
restriction(s):
restriction(s):
5
4 2


2
3x 3
6x
2  7 r 1  5r 3

 r
9
6
2
c) LCD = _____________________
restriction(s):
3
y 5
1


2
8 y  4 2 y  y 10 y  5
V. Solve for the indicated variable.(5pts)
LR L R
a) 1 1  2 2 for P1
P1
P2
VI. (5pts) Dr. Dre can type 46 words per minute. How many words would he type in ¼ hour (15min)?
VII. Simplify. (2pts each)
a)
25
49
b)  3  27
c)  3
Page 2
1
125
d)
(76) 2
6/28/2017
Spring 2006
Math 80 Exam 3
Name_____________
150pts Show work for credit
BOX ANSWER!
XIII. Simplify the radicals. Assume all variables represent positive real numbers.(3pts)
a)
36n 2
d)
a 15
4
b)
3
72a 6 b18
c)
e)
3
4
x 8 y 10 z 17
n8
27
IX. Simplify completely. (2pts each)
a) 49 2
b) (49)
1
 16 
e)  
 25 
2
c) 49 2
1
2
d) 49 2
1
 32
X. Write in
a) 5n
1
Radical form with positive exponents.(2pts each)
b)  9 x  7
d) (n 4  16) 
c) (2 y )  5  8 x
2
3
3
4
3
2
4
Page 3
6/28/2017
Spring 2006
Math 80 Exam 3
Name_____________
150pts Show work for credit
BOX ANSWER!
XI. Simplify. Express answers with positive exponents. (4pts each)
c  10
b)
1
c5
3
2
6  3 2
a) (a b )
 ab
4
18r 3t (t 97 r 37 )0
c)
5
2
12(r 3 t  9 ) 18
3
2
d) 4b (2b
1
2
 7b 2 )b0
1
XII. Rationalize the denominator.(5pts)
a)
3
9 5
XIII. Multiply, add or subtract, rationalize.(4pts)
a)  12 *  12
c) (7+8i) - (-6+i)
b) (8-3i)(2+5i)
d)
6  2i
9  3i
XIV. Graph the function and give the domain and its range.(8pts)
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6/28/2017
Spring 2006
Math 80 Exam 3
Name_____________
150pts Show work for credit
BOX ANSWER!
f ( x)  x  5
D:
R:
Extra credit, 8 pts , pick ONE and circle it !
1) The speed of a stream is 5mph. If a boat travels 52 miles downstream in the same time that it takes to
travel 26 miles upstream, what is the speed of the boat in still water. ? Set up 4 pts, solving and
answering the problem 4pts
Distance
Rate
Time
Downstream 52miles
Upstream
26miles
2) Solve the equation:
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6/28/2017
Spring 2006
Math 80 Exam 3
Name_____________
150pts Show work for credit
BOX ANSWER!
2 x  11  4 x  2
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