<< Chapter < Page Chapter >> Page >

Classify the equation as a conditional equation, an identity, or a contradiction and then state the solution:

8 ( 1 3 x ) + 15 ( 2 x + 7 ) = 2 ( x + 50 ) + 4 ( x + 3 ) + 1

identity; all real numbers

Got questions? Get instant answers now!

Classify as a conditional equation, an identity, or a contradiction. Then state the solution.

10 + 4 ( p 5 ) = 0

Solution

.
Distribute. .
Combine like terms. .
Add 10 to both sides. .
Simplify. .
Divide. .
Simplify. .
The equation is true when p = 5 2 . This is a conditional equation.
The solution is p = 5 2 .
Got questions? Get instant answers now!
Got questions? Get instant answers now!

Classify the equation as a conditional equation, an identity, or a contradiction and then state the solution: 11 ( q + 3 ) 5 = 19

conditional equation; q = 9 11

Got questions? Get instant answers now!

Classify the equation as a conditional equation, an identity, or a contradiction and then state the solution: 6 + 14 ( k 8 ) = 95

conditional equation; k = 193 14

Got questions? Get instant answers now!

Classify the equation as a conditional equation, an identity, or a contradiction. Then state the solution.

5 m + 3 ( 9 + 3 m ) = 2 ( 7 m 11 )

Solution

.
Distribute. .
Combine like terms. .
Subtract 14 m from both sides. .
Simplify. .
But 27 −22 . The equation is a contradiction.
It has no solution.
Got questions? Get instant answers now!
Got questions? Get instant answers now!

Classify the equation as a conditional equation, an identity, or a contradiction and then state the solution:

12 c + 5 ( 5 + 3 c ) = 3 ( 9 c 4 )

contradiction; no solution

Got questions? Get instant answers now!

Classify the equation as a conditional equation, an identity, or a contradiction and then state the solution:

4 ( 7 d + 18 ) = 13 ( 3 d 2 ) 11 d

contradiction; no solution

Got questions? Get instant answers now!
Type of equation What happens when you solve it? Solution
Conditional Equation True for one or more values of the variables and false for all other values One or more values
Identity True for any value of the variable All real numbers
Contradiction False for all values of the variable No solution

Key concepts

  • General Strategy for Solving Linear Equations
    1. Simplify each side of the equation as much as possible.
      Use the Distributive Property to remove any parentheses.
      Combine like terms.
    2. Collect all the variable terms on one side of the equation.
      Use the Addition or Subtraction Property of Equality.
    3. Collect all the constant terms on the other side of the equation.
      Use the Addition or Subtraction Property of Equality.
    4. Make the coefficient of the variable term to equal to 1.
      Use the Multiplication or Division Property of Equality.
      State the solution to the equation.
    5. Check the solution.
      Substitute the solution into the original equation.

Practice makes perfect

Solve Equations Using the General Strategy for Solving Linear Equations

In the following exercises, solve each linear equation.

21 ( y 5 ) = −42

y = 3

Got questions? Get instant answers now!

−16 ( 3 n + 4 ) = 32

n = −2

Got questions? Get instant answers now!

5 ( 8 + 6 p ) = 0

p = 4 3

Got questions? Get instant answers now!

( t 19 ) = 28

t = −9

Got questions? Get instant answers now!

8 ( 9 b 4 ) 12 = 100

b = 2

Got questions? Get instant answers now!

21 + 2 ( m 4 ) = 25

m = 6

Got questions? Get instant answers now!

−6 + 6 ( 5 k ) = 15

k = 3 2

Got questions? Get instant answers now!

2 ( 9 s 6 ) 62 = 16

Got questions? Get instant answers now!

8 ( 6 t 5 ) 35 = −27

t = 1

Got questions? Get instant answers now!

3 ( 10 2 x ) + 54 = 0

Got questions? Get instant answers now!

−2 ( 11 7 x ) + 54 = 4

x = −2

Got questions? Get instant answers now!

3 5 ( 10 x 5 ) = 27

x = 5

Got questions? Get instant answers now!

1 5 ( 15 c + 10 ) = c + 7

Got questions? Get instant answers now!

1 4 ( 20 d + 12 ) = d + 7

d = 1

Got questions? Get instant answers now!

18 ( 9 r + 7 ) = −16

Got questions? Get instant answers now!

15 ( 3 r + 8 ) = 28

r = −7

Got questions? Get instant answers now!

−3 ( m 1 ) = 13

m = −15

Got questions? Get instant answers now!

11 4 ( y 8 ) = 43

Got questions? Get instant answers now!

18 2 ( y 3 ) = 32

y = −4

Got questions? Get instant answers now!

24 8 ( 3 v + 6 ) = 0

Got questions? Get instant answers now!

35 5 ( 2 w + 8 ) = −10

w = 1 2

Got questions? Get instant answers now!

4 ( a 12 ) = 3 ( a + 5 )

Got questions? Get instant answers now!

−2 ( a 6 ) = 4 ( a 3 )

a = 4

Got questions? Get instant answers now!

2 ( 5 u ) = −3 ( 2 u + 6 )

Got questions? Get instant answers now!

5 ( 8 r ) = −2 ( 2 r 16 )

r = 8

Got questions? Get instant answers now!

3 ( 4 n 1 ) 2 = 8 n + 3

Got questions? Get instant answers now!

9 ( 2 m 3 ) 8 = 4 m + 7

m = 3

Got questions? Get instant answers now!

12 + 2 ( 5 3 y ) = −9 ( y 1 ) 2

Got questions? Get instant answers now!

−15 + 4 ( 2 5 y ) = −7 ( y 4 ) + 4

y = −3

Got questions? Get instant answers now!

8 ( x 4 ) 7 x = 14

Got questions? Get instant answers now!

5 ( x 4 ) 4 x = 14

x = 34

Got questions? Get instant answers now!

5 + 6 ( 3 s 5 ) = −3 + 2 ( 8 s 1 )

Got questions? Get instant answers now!

−12 + 8 ( x 5 ) = −4 + 3 ( 5 x 2 )

x = −6

Got questions? Get instant answers now!

4 ( u 1 ) 8 = 6 ( 3 u 2 ) 7

Got questions? Get instant answers now!

7 ( 2 n 5 ) = 8 ( 4 n 1 ) 9

n = −1

Got questions? Get instant answers now!

4 ( p 4 ) ( p + 7 ) = 5 ( p 3 )

Got questions? Get instant answers now!

3 ( a 2 ) ( a + 6 ) = 4 ( a 1 )

a = −4

Got questions? Get instant answers now!

( 9 y + 5 ) ( 3 y 7 )
= 16 ( 4 y 2 )

Got questions? Get instant answers now!

( 7 m + 4 ) ( 2 m 5 )
= 14 ( 5 m 3 )

m = −4

Got questions? Get instant answers now!

4 [ 5 8 ( 4 c 3 ) ]
= 12 ( 1 13 c ) 8

Got questions? Get instant answers now!

5 [ 9 2 ( 6 d 1 ) ]
= 11 ( 4 10 d ) 139

d = −3

Got questions? Get instant answers now!

3 [ −9 + 8 ( 4 h 3 ) ]
= 2 ( 5 12 h ) 19

Got questions? Get instant answers now!

3 [ −14 + 2 ( 15 k 6 ) ]
= 8 ( 3 5 k ) 24

k = 3 5

Got questions? Get instant answers now!

5 [ 2 ( m + 4 ) + 8 ( m 7 ) ]
= 2 [ 3 ( 5 + m ) ( 21 3 m ) ]

Got questions? Get instant answers now!

10 [ 5 ( n + 1 ) + 4 ( n 1 ) ]
= 11 [ 7 ( 5 + n ) ( 25 3 n ) ]

n = −5

Got questions? Get instant answers now!

5 ( 1.2 u 4.8 ) = −12

Got questions? Get instant answers now!

4 ( 2.5 v 0.6 ) = 7.6

v = 1

Got questions? Get instant answers now!

0.25 ( q 6 ) = 0.1 ( q + 18 )

Got questions? Get instant answers now!

0.2 ( p 6 ) = 0.4 ( p + 14 )

p = −34

Got questions? Get instant answers now!

0.5 ( 16 m + 34 ) = −15

m = −4

Got questions? Get instant answers now!

Classify Equations

In the following exercises, classify each equation as a conditional equation, an identity, or a contradiction and then state the solution.

23 z + 19 = 3 ( 5 z 9 ) + 8 z + 46

Got questions? Get instant answers now!

15 y + 32 = 2 ( 10 y 7 ) 5 y + 46

identity; all real numbers

Got questions? Get instant answers now!

5 ( b 9 ) + 4 ( 3 b + 9 ) = 6 ( 4 b 5 ) 7 b + 21

Got questions? Get instant answers now!

9 ( a 4 ) + 3 ( 2 a + 5 ) = 7 ( 3 a 4 ) 6 a + 7

identity; all real numbers

Got questions? Get instant answers now!

18 ( 5 j 1 ) + 29 = 47

Got questions? Get instant answers now!

24 ( 3 d 4 ) + 100 = 52

conditional equation; d = 2 3

Got questions? Get instant answers now!

22 ( 3 m 4 ) = 8 ( 2 m + 9 )

Got questions? Get instant answers now!

30 ( 2 n 1 ) = 5 ( 10 n + 8 )

conditional equation; n = 7

Got questions? Get instant answers now!

7 v + 42 = 11 ( 3 v + 8 ) 2 ( 13 v 1 )

Got questions? Get instant answers now!

18 u 51 = 9 ( 4 u + 5 ) 6 ( 3 u 10 )

contradiction; no solution

Got questions? Get instant answers now!

3 ( 6 q 9 ) + 7 ( q + 4 ) = 5 ( 6 q + 8 ) 5 ( q + 1 )

Got questions? Get instant answers now!

5 ( p + 4 ) + 8 ( 2 p 1 ) = 9 ( 3 p 5 ) 6 ( p 2 )

contradiction; no solution

Got questions? Get instant answers now!

12 ( 6 h 1 ) = 8 ( 8 h + 5 ) 4

Got questions? Get instant answers now!

9 ( 4 k 7 ) = 11 ( 3 k + 1 ) + 4

conditional equation; k = 26

Got questions? Get instant answers now!

45 ( 3 y 2 ) = 9 ( 15 y 6 )

Got questions? Get instant answers now!

60 ( 2 x 1 ) = 15 ( 8 x + 5 )

contradiction; no solution

Got questions? Get instant answers now!

16 ( 6 n + 15 ) = 48 ( 2 n + 5 )

Got questions? Get instant answers now!

36 ( 4 m + 5 ) = 12 ( 12 m + 15 )

identity; all real numbers

Got questions? Get instant answers now!

9 ( 14 d + 9 ) + 4 d = 13 ( 10 d + 6 ) + 3

Got questions? Get instant answers now!

11 ( 8 c + 5 ) 8 c = 2 ( 40 c + 25 ) + 5

identity; all real numbers

Got questions? Get instant answers now!

Everyday math

Fencing Micah has 44 feet of fencing to make a dog run in his yard. He wants the length to be 2.5 feet more than the width. Find the length, L , by solving the equation 2 L + 2 ( L 2.5 ) = 44 .

Got questions? Get instant answers now!

Coins Rhonda has $1.90 in nickels and dimes. The number of dimes is one less than twice the number of nickels. Find the number of nickels, n , by solving the equation 0.05 n + 0.10 ( 2 n 1 ) = 1.90 .

8 nickels

Got questions? Get instant answers now!

Writing exercises

Using your own words, list the steps in the general strategy for solving linear equations.

Got questions? Get instant answers now!

Explain why you should simplify both sides of an equation as much as possible before collecting the variable terms to one side and the constant terms to the other side.

Answers will vary.

Got questions? Get instant answers now!

What is the first step you take when solving the equation 3 7 ( y 4 ) = 38 ? Why is this your first step?

Got questions? Get instant answers now!

Solve the equation 1 4 ( 8 x + 20 ) = 3 x 4 explaining all the steps of your solution as in the examples in this section.

Answers will vary.

Got questions? Get instant answers now!

Self check

After completing the exercises, use this checklist to evaluate your mastery of the objective of this section.

This is a table that has three rows and four columns. In the first row, which is a header row, the cells read from left to right: “I can…,” “confidently,” “with some help,” and “no-I don’t get it!” The first column below “I can…” reads: “solve equations using the general strategy for solving linear equations,” and “classify equations.” The rest of the cells are blank.

On a scale of 1-10, how would you rate your mastery of this section in light of your responses on the checklist? How can you improve this?

Questions & Answers

A golfer on a fairway is 70 m away from the green, which sits below the level of the fairway by 20 m. If the golfer hits the ball at an angle of 40° with an initial speed of 20 m/s, how close to the green does she come?
Aislinn Reply
cm
tijani
what is titration
John Reply
what is physics
Siyaka Reply
A mouse of mass 200 g falls 100 m down a vertical mine shaft and lands at the bottom with a speed of 8.0 m/s. During its fall, how much work is done on the mouse by air resistance
Jude Reply
Can you compute that for me. Ty
Jude
what is the dimension formula of energy?
David Reply
what is viscosity?
David
what is inorganic
emma Reply
what is chemistry
Youesf Reply
what is inorganic
emma
Chemistry is a branch of science that deals with the study of matter,it composition,it structure and the changes it undergoes
Adjei
please, I'm a physics student and I need help in physics
Adjanou
chemistry could also be understood like the sexual attraction/repulsion of the male and female elements. the reaction varies depending on the energy differences of each given gender. + masculine -female.
Pedro
A ball is thrown straight up.it passes a 2.0m high window 7.50 m off the ground on it path up and takes 1.30 s to go past the window.what was the ball initial velocity
Krampah Reply
2. A sled plus passenger with total mass 50 kg is pulled 20 m across the snow (0.20) at constant velocity by a force directed 25° above the horizontal. Calculate (a) the work of the applied force, (b) the work of friction, and (c) the total work.
Sahid Reply
you have been hired as an espert witness in a court case involving an automobile accident. the accident involved car A of mass 1500kg which crashed into stationary car B of mass 1100kg. the driver of car A applied his brakes 15 m before he skidded and crashed into car B. after the collision, car A s
Samuel Reply
can someone explain to me, an ignorant high school student, why the trend of the graph doesn't follow the fact that the higher frequency a sound wave is, the more power it is, hence, making me think the phons output would follow this general trend?
Joseph Reply
Nevermind i just realied that the graph is the phons output for a person with normal hearing and not just the phons output of the sound waves power, I should read the entire thing next time
Joseph
Follow up question, does anyone know where I can find a graph that accuretly depicts the actual relative "power" output of sound over its frequency instead of just humans hearing
Joseph
"Generation of electrical energy from sound energy | IEEE Conference Publication | IEEE Xplore" ***ieeexplore.ieee.org/document/7150687?reload=true
Ryan
what's motion
Maurice Reply
what are the types of wave
Maurice
answer
Magreth
progressive wave
Magreth
hello friend how are you
Muhammad Reply
fine, how about you?
Mohammed
hi
Mujahid
A string is 3.00 m long with a mass of 5.00 g. The string is held taut with a tension of 500.00 N applied to the string. A pulse is sent down the string. How long does it take the pulse to travel the 3.00 m of the string?
yasuo Reply
Who can show me the full solution in this problem?
Reofrir Reply
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply
Practice Key Terms 3

Get Jobilize Job Search Mobile App in your pocket Now!

Get it on Google Play Download on the App Store Now




Source:  OpenStax, Elementary algebra. OpenStax CNX. Jan 18, 2017 Download for free at http://cnx.org/content/col12116/1.2
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Elementary algebra' conversation and receive update notifications?

Ask