Download 2-5 Practice A

Name ________________________________________ Date __________________ Class__________________
LESSON
2-5
Practice A
Solving for a Variable
Answer each of the following.
1. The formula K = C + 273 is used to
convert temperatures from degrees
Celsius to Kelvin. Solve this formula
for C.
1
relates the period of
f
a sound wave T to its frequency f.
Solve this formula for f.
2. The formula T =
_________________________________________
________________________________________
Solve for the indicated variable.
3. x = 5y for y
4. s + 4t = r for s
________________________
6. 6 = hj + k for j
________________________
5. 3m − 7n = p for m
_________________________
v
= 9 for w
w
7.
________________________
8.
_________________________
a+3
= c for a
b
________________________
Answer each of the following.
9. The formula d = rt relates the distance an
object travels d, to its average rate of speed r,
and amount of time t that it travels.
a. Solve the formula d = rt for t.
_________________________________
b. How many hours would it take for a car
to travel 150 miles at an average rate of
50 miles per hour?
_________________________________
10. The formula F − E + V = 2 relates the number of
faces F, edges E, and vertices V, in any convex
polyhedron.
a. Solve the formula F − E + V = 2 for F.
________________________________
b. How many faces does a polyhedron with
20 vertices and 30 edges have?
________________________________
Original content Copyright © by Holt McDougal. Additions and changes to the original content are the responsibility of the instructor.
2-35
Holt McDougal Algebra 1
Problem Solving
Practice C
1. x = 2
2. a = 3
3. c = −1
4. y = −3
5. d = −
11
2
7. m = 9
9. no solution
11. 6 shirts, $61
1.
3.
5.
7.
6. t = −2
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
10. all real numbers
12. 5 weeks, $85
Review for Mastery
1. Possible answers: add −3x to each side,
add −7x to each side
2. Possible answers: add 4x to each side,
add 10x to each side
LESSON 2–5
3. Possible answers: add 3x to each side,
add −15x to each side
5. 2
6. 5
7. no solution
8. 1
9. all real numbers
10. no solution
Practice A
1. C = K − 273
3. y =
11. all real numbers
12. −1
1
3. x = 7
2
2. x = −4
4. x = −2
4. s = r − 4t
6. j =
7. w =
v
9
8. a = bc − 3
d
r
b. 3
6−k
h
10. a. F = 2 + E − V
b. 12
Practice B
6. 9x + 18 = 0 or −9x + (−18) = 0
7. 5x + 27 = 0 or −5x + (−27) = 0
8. 3x + (−21) = 0 or −3x + 21 = 0
b
9. a. x = −
a
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.
2
12. x = −5
5
1
T
p + 7n
3
9. a. t =
5. 2x + (−6) = 0 or −2x + 6 = 0
10. x = 3
x
5
2. f =
5. m =
Challenge
7
1. x = −
3
2. 7 days
4. 20 months
6. G
Reading Strategies
8. all real numbers
4. −48
28 feet
16 hours
B
C
11. x = −2
C
2π
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 =
13. x = 7
b. 17
14. a. infinitely many solutions
y −b
x
1. r =
c − 215
5
10. a. b =
2A
h
b. 32 mm
b. no solution
Original content Copyright © by Holt McDougal. Additions and changes to the original content are the responsibility of the instructor.
A17
Holt McDougal Algebra 1