Solve the Inequality
Graph the Inequality
Word Problems
100

-12 > x - 7

-12 > x - 7

-12 + 7 > x 

-5 > x

100

Graph the solved inequality:

-1 + r ≥ 4

-1 + r ≥ 4

r ≥ 5

solid dot on 5 and shaded to the right (6,7,8, etc)

100

Write the inequality:

Brett has a $30 online gift voucher. He plans to buy as many books as he can. The cost of each book is $4. There is also a single shipping charge of $2. How many books can he afford without spending more than his gift voucher amount?

$4 * book + $2 = amount Brett spends on books

He wants to spend no more than his voucher, so he wants to spend less than or equal to that amount.

4b + 2 ≤ 30

200

-3x > 3

-3x > 3

-3x/-3 > 3/-3

x < -1

200

Graph the solved inequality:

k /4 < -4

k /4 < -4

k < -16

open dot on -16 and shaded to the left (-17,-18,-19...)

200

Write the inequality:

Lucas is offered either 15% off or $21 off his total shopping bill. How much would have to be spent to make the 15% option the best one?

15% = .15

We want 15% off the bill to make the bill less than if you took $21 off. 

.15 * bill < b - 21

300

2x + 4 ≥ 24

2x + 4 ≥ 24

2x ≥ 24- 4

2x ≥ 20

x ≥ 20/2

x ≥ 10

300

Graph the solved inequality:

-4b - 5 > -25

-4b - 5 > -25

-4b > -20

b < 5

open circle on 5 and shaded to the left

300

Solve the word problem.

Sid is $300 in debt. He needs to get the debt down to no more than $100 within the next 8 months. If he pays the same amount each month, what is the minimum he must pay off each month to manage this?

300 = current debt

8 * amount he pays per month will be taken out of that debt

He needs the debt to be less than or equal to $100.

300 - 8m ≤ 100

-8m ≤ 100 - 300

-8m ≤ -200

m ≥ -200/-8

m ≥ 25

The minimum he could pay each month is $25. 

400

-90 ≥ -5 (k - 3)

-90 ≥ -5 (k - 3)

-90/-5 ≤ k- 3

18 ≤ k - 3

18 + 3 ≤ k

21 ≤ k

400

Graph the solved inequality:

(-8 + r) / 2 > -8

(-8 + r) / 2 > -8

-8 + r > -16

r > -8

open circle on -8 and shaded to the right (-7,-6,-5...)

400

Solve the word problem:

The sum of two consecutive integers is at least negative fifteen.  What are the smallest values of consecutive integers  that will make this true?

Consecutive numbers are numbers in a row (ex: 3,4,5).  If the first number is x, the next number is x + 1.

x + (x + 1) ≥ -15

2x + 1 ≥ -15

2x ≥ -15 -1

2x ≥ -16

x ≥ -16/2

x ≥ -8

The smallest value of the integers are -8 and -7 (-8 +1)

500

-3 - 6(4x + 6) > -111

-3 - 6(4x + 6) > -111

-6(4x + 6) > -111 + 3

-6(4x + 6) > -108

(4x + 6) < -108/-6

4x + 6 < 18

4x < 18 - 6

4x <12

x < 12/4

x < 3


500

Graph the solved inequality:

-5n + 6 ≥ -7(5n - 6) - 6n


-5n + 6 ≥ -7(5n - 6) - 6n

-5n + 6 + 6n ≥ -7(5n - 6) 

 6 + n ≥ -7(5n - 6) 

6 + n ≥ -35n + 42

6 + n + 35n ≥ 42

6 + 36n ≥ 42

36n ≥ 42 - 6

36n ≥ 36

n ≥ 36/36

n ≥ 1

solid circle on 1 and shaded to the right (2,3,4...)


 

500

Solve the word problem:

Commission or salary: Jill has a job offer. She is offered either $50 per day or $30 per day plus a commission of $3 for every plant she sells. How many plants does she need to sell to make the commission offer the best paying option, assuming she works the same number of days?

$50d < $30d + $3p

$50d - $30d < $3p

$20d < $3p

$20d/ $3 < p

20/3 d < p

6.67 d < p

The number of plants must be 7x greater (you cannot sell a fraction of a plant) than the number of days she words OR the commission makes sense if she is selling at least 7 plants a day.