Download Homework handout 10.5

Name _______________________________________ Date __________________ Class __________________
Practice B
Solving for a Variable
Answer each of the following.
1. The formula C  2r relates the radius r
of a circle to its circumference C. Solve
the formula for r.
2. The formula y  mx  b is called the
slope-intercept form of a line. Solve this
formula for m.
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Solve for the indicated variable.
3. 4c  d for c
4. n  6m  8 for n
________________________
5. 2p  5r  q for p
________________________
6. 10  xy  z for x
7.
________________________
a
 c for b
b
________________________
8.
________________________
h4
 k for j
j
________________________
Answer each of the following.
9. The formula c  5p  215 relates c, the total cost
in dollars of hosting a birthday party at a skating
rink, to p, the number of people attending.
a. Solve the formula c  5p  215 for p.
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b. If Allie’s parents are willing to spend $300 for
a party, how many people can attend?
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1
bh,
2
where b represents the length of the base and h
represents the height.
10. The formula for the area of a triangle is A 
a. Solve the formula A 
1
bh for b.
2
b. If a triangle has an area of 192 mm2, and the
height measures 12 mm, what is the measure
of the base?
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Original content Copyright © by Holt McDougal. Additions and changes to the original content are the responsibility of the instructor.
Holt McDougal Algebra 1
Name _______________________________________ Date __________________ Class __________________
3.Possible answers: add 3x to each side, add
15x to each side
4. 48
5. 2
6. 5
7. no solution
8. 1
9. all real numbers
10. no solution
11. all real numbers
12. 1
SOLVING FOR A VARIABLE
Practice A
1. C  K  273
x
5
3. y 
2. x  4
1
3. x  7
2
4. x  2
5. 2x  (6)  0 or 2x  6  0
6. 9x  18  0 or 9x  (18)  0
7. 5x  27  0 or 5x  (27)  0
b. After writing the equation in the form
ax  b  0, substitute the values of a
and b into the formula found in part a.
10. x  3
12. x  5
6. j 
7. w 
v
9
8. a  bc  3
9. a. t 
13. x  7
14. a. infinitely many solutions
10. a. F  2  E  V
b. 12
Practice B
y b
x
1. r 
C
2
2. m 
3. c 
d
4
4. n  8  6m
5. p 
q  5r
2
6. x 
10  z
y
7. b 
a
c
8. j 
h4
k
9. a. p 
c  215
5
b. 17
1. w 
Problem Solving
28 feet
16 hours
B
C
6k
h
10. a. b 
2A
h
b. 32 mm
Practice C
b. no solution
1.
3.
5.
7.
d
r
b. 3
11. x  2
2
5
4. s  r  4t
p  7n
3
8. 3x  (21)  0 or 3x  21  0
b
9. a. x  
a
1
T
5. m 
Challenge
7
1. x  
3
2. f 
2. 7 days
4. 20 months
6. G
Reading Strategies
1. Look for an opportunity to use the
Distributive Property.
2. Combine any like terms.
3. Collect the variable terms on one side of
the equal sign.
4. p  6
5. x  1
6. t  2
P  2l
2
2. vf  at  vi
3. f 
g
3
4. a  12  5b
5. x 
z  7y
3
6. h 
jk  g
5
7. r  s(t  9)
8. n 
m3
p
9. a. a 
F
m
b. 19 m/s2
10. a. t 
I
Pr
b. 8 years
Original content Copyright © by Holt McDougal. Additions and changes to the original content are the responsibility of the instructor.
Holt McDougal Algebra 1