<< Chapter < Page Chapter >> Page >

Andreas bought a used car for $12,000. Because the car was 4-years old, its price was 3 4 of the original price, when the car was new. What was the original price of the car?

Solution

What are you asked to find? The original price of the car Assign a variable. Let p = the original price . Write a sentence that gives the information to find it. $12,000 is 3 4 of the original price. Translate into an equation. Solve. 12,000 = 3 4 p 4 3 ( 12,000 ) = 4 3 · 3 4 p 16,000 = p The original cost of the car was $16,000. Check: Is 3 4 of $16,000 equal to $12,000? 3 4 · 16,000 = ? 12,000 12,000 = 12,000

Got questions? Get instant answers now!
Got questions? Get instant answers now!

Translate and solve:

The annual property tax on the Mehta’s house is $1,800, calculated as 15 1,000 of the assessed value of the house. What is the assessed value of the Mehta’s house?

$120,000

Got questions? Get instant answers now!

Translate and solve:

Stella planted 14 flats of flowers in 2 3 of her garden. How many flats of flowers would she need to fill the whole garden?

21 flats

Got questions? Get instant answers now!

Key concepts

  • The Division Property of Equality —For any numbers a , b , and c , and c 0 , if a = b , then a c = b c .
    When you divide both sides of an equation by any non-zero number, you still have equality.
  • The Multiplication Property of Equality —For any numbers a , b , and c , if a = b , then a c = b c .
    If you multiply both sides of an equation by the same number, you still have equality.

Practice makes perfect

Solve Equations Using the Division and Multiplication Properties of Equality

In the following exercises, solve each equation using the Division and Multiplication Properties of Equality and check the solution.

−809 = 15 y

y = 809 15

Got questions? Get instant answers now!

−37 p = −541

p = 541 37

Got questions? Get instant answers now!

5 8 w = 40

w = −64

Got questions? Get instant answers now!

2 5 = 1 10 a

a = −4

Got questions? Get instant answers now!

7 10 x = 14 3

x = 20 3

Got questions? Get instant answers now!

7 12 = 3 4 p

p = 7 9

Got questions? Get instant answers now!

5 18 = 10 9 u

u = 1 4

Got questions? Get instant answers now!

Solve Equations That Require Simplification

In the following exercises, solve each equation requiring simplification.

100 16 = 4 p 10 p p

p = −12

Got questions? Get instant answers now!

−18 7 = 5 t 9 t 6 t

Got questions? Get instant answers now!

7 8 n 3 4 n = 9 + 2

n = 88

Got questions? Get instant answers now!

5 12 q + 1 2 q = 25 3

Got questions? Get instant answers now!

0.25 d + 0.10 d = 6 0.75

d = 15

Got questions? Get instant answers now!

0.05 p 0.01 p = 2 + 0.24

Got questions? Get instant answers now!

−10 ( q 4 ) 57 = 93

q = −11

Got questions? Get instant answers now!

−12 ( d 5 ) 29 = 43

Got questions? Get instant answers now!

−10 ( x + 4 ) 19 = 85

x = 72 5

Got questions? Get instant answers now!

−15 ( z + 9 ) 11 = 75

Got questions? Get instant answers now!

Mixed Practice

In the following exercises, solve each equation.

c 0.3 c = 35.70

c = 51

Got questions? Get instant answers now!

Translate to an Equation and Solve

In the following exercises, translate to an equation and then solve.

187 is the product of −17 and m .

Got questions? Get instant answers now!

133 is the product of −19 and n .

133 = −19 n ; n = −7

Got questions? Get instant answers now!

−184 is the product of 23 and p .

Got questions? Get instant answers now!

−152 is the product of 8 and q .

−152 = 8 q ; q = −19

Got questions? Get instant answers now!

u divided by 7 is equal to −49 .

Got questions? Get instant answers now!

r divided by 12 is equal to −48 .

r 12 = −48 ; r = −576

Got questions? Get instant answers now!

h divided by −13 is equal to −65 .

Got questions? Get instant answers now!

j divided by −20 is equal to −80 .

j −20 = −80 ; j = 1,600

Got questions? Get instant answers now!

The quotient c and −19 is 38.

Got questions? Get instant answers now!

The quotient of b and −6 is 18.

b −6 = 18 ; b = −108

Got questions? Get instant answers now!

The quotient of h and 26 is −52 .

Got questions? Get instant answers now!

The quotient k and 22 is −66 .

k 22 = −66 ; k = −1,452

Got questions? Get instant answers now!

Three-tenths of x is 15.

3 10 x = 15 ; x = 50

Got questions? Get instant answers now!

Five-halves of v is 50.

5 2 v = 50 ; v = 20

Got questions? Get instant answers now!

The sum of nine-tenths and g is two-thirds.

Got questions? Get instant answers now!

The sum of two-fifths and f is one-half.

2 5 + f = 1 2 ; f = 1 10

Got questions? Get instant answers now!

The difference of p and one-sixth is two-thirds.

Got questions? Get instant answers now!

The difference of q and one-eighth is three-fourths.

q 1 8 = 3 4 ; q = 7 8

Got questions? Get instant answers now!

Translate and Solve Applications

In the following exercises, translate into an equation and solve.

Kindergarten Connie’s kindergarten class has 24 children. She wants them to get into 4 equal groups. How many children will she put in each group?

Got questions? Get instant answers now!

Balloons Ramona bought 18 balloons for a party. She wants to make 3 equal bunches. How many balloons did she use in each bunch?

6 balloons

Got questions? Get instant answers now!

Tickets Mollie paid $36.25 for 5 movie tickets. What was the price of each ticket?

Got questions? Get instant answers now!

Shopping Serena paid $12.96 for a pack of 12 pairs of sport socks. What was the price of pair of sport socks?

$1.08

Got questions? Get instant answers now!

Sewing Nancy used 14 yards of fabric to make flags for one-third of the drill team. How much fabric, would Nancy need to make flags for the whole team?

Got questions? Get instant answers now!

MPG John’s SUV gets 18 miles per gallon (mpg). This is half as many mpg as his wife’s hybrid car. How many miles per gallon does the hybrid car get?

36 mpg

Got questions? Get instant answers now!

Height Aiden is 27 inches tall. He is 3 8 as tall as his father. How tall is his father?

Got questions? Get instant answers now!

Real estate Bea earned $11,700 commission for selling a house, calculated as 6 100 of the selling price. What was the selling price of the house?

$195,000

Got questions? Get instant answers now!

Everyday math

Commission Every week Perry gets paid $150 plus 12% of his total sales amount. Solve the equation 840 = 150 + 0.12 ( a 1250 ) for a , to find the total amount Perry must sell in order to be paid $840 one week.

Got questions? Get instant answers now!

Stamps Travis bought $9.45 worth of 49-cent stamps and 21-cent stamps. The number of 21-cent stamps was 5 less than the number of 49-cent stamps. Solve the equation 0.49 s + 0.21 ( s 5 ) = 9.45 for s , to find the number of 49-cent stamps Travis bought.

15 49-cent stamps

Got questions? Get instant answers now!

Writing exercises

Frida started to solve the equation −3 x = 36 by adding 3 to both sides. Explain why Frida’s method will not solve the equation.

Got questions? Get instant answers now!

Emiliano thinks x = 40 is the solution to the equation 1 2 x = 80 . Explain why he is wrong.

Answers will vary.

Got questions? Get instant answers now!

Self check

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

This is a table that has five 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 “1) solve equations using the Division and Multiplication Properties of equality,” “2) solve equations that require simplification,” “3) translate to an equation and solve,” and “4) translate and solve applications.” The rest of the cells are blank.

What does this checklist tell you about your mastery of this section? What steps will you take to improve?

Questions & Answers

what does preconceived mean
sammie Reply
physiological Psychology
Nwosu Reply
How can I develope my cognitive domain
Amanyire Reply
why is communication effective
Dakolo Reply
Communication is effective because it allows individuals to share ideas, thoughts, and information with others.
effective communication can lead to improved outcomes in various settings, including personal relationships, business environments, and educational settings. By communicating effectively, individuals can negotiate effectively, solve problems collaboratively, and work towards common goals.
it starts up serve and return practice/assessments.it helps find voice talking therapy also assessments through relaxed conversation.
miss
Every time someone flushes a toilet in the apartment building, the person begins to jumb back automatically after hearing the flush, before the water temperature changes. Identify the types of learning, if it is classical conditioning identify the NS, UCS, CS and CR. If it is operant conditioning, identify the type of consequence positive reinforcement, negative reinforcement or punishment
Wekolamo Reply
please i need answer
Wekolamo
because it helps many people around the world to understand how to interact with other people and understand them well, for example at work (job).
Manix Reply
Agreed 👍 There are many parts of our brains and behaviors, we really need to get to know. Blessings for everyone and happy Sunday!
ARC
A child is a member of community not society elucidate ?
JESSY Reply
Isn't practices worldwide, be it psychology, be it science. isn't much just a false belief of control over something the mind cannot truly comprehend?
Simon Reply
compare and contrast skinner's perspective on personality development on freud
namakula Reply
Skinner skipped the whole unconscious phenomenon and rather emphasized on classical conditioning
war
explain how nature and nurture affect the development and later the productivity of an individual.
Amesalu Reply
nature is an hereditary factor while nurture is an environmental factor which constitute an individual personality. so if an individual's parent has a deviant behavior and was also brought up in an deviant environment, observation of the behavior and the inborn trait we make the individual deviant.
Samuel
I am taking this course because I am hoping that I could somehow learn more about my chosen field of interest and due to the fact that being a PsyD really ignites my passion as an individual the more I hope to learn about developing and literally explore the complexity of my critical thinking skills
Zyryn Reply
good👍
Jonathan
and having a good philosophy of the world is like a sandwich and a peanut butter 👍
Jonathan
generally amnesi how long yrs memory loss
Kelu Reply
interpersonal relationships
Abdulfatai Reply
What would be the best educational aid(s) for gifted kids/savants?
Heidi Reply
treat them normal, if they want help then give them. that will make everyone happy
Saurabh
What are the treatment for autism?
Magret Reply
hello. autism is a umbrella term. autistic kids have different disorder overlapping. for example. a kid may show symptoms of ADHD and also learning disabilities. before treatment please make sure the kid doesn't have physical disabilities like hearing..vision..speech problem. sometimes these
Jharna
continue.. sometimes due to these physical problems..the diagnosis may be misdiagnosed. treatment for autism. well it depends on the severity. since autistic kids have problems in communicating and adopting to the environment.. it's best to expose the child in situations where the child
Jharna
child interact with other kids under doc supervision. play therapy. speech therapy. Engaging in different activities that activate most parts of the brain.. like drawing..painting. matching color board game. string and beads game. the more you interact with the child the more effective
Jharna
results you'll get.. please consult a therapist to know what suits best on your child. and last as a parent. I know sometimes it's overwhelming to guide a special kid. but trust the process and be strong and patient as a parent.
Jharna
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

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