topic badge
CanadaON
Grade 8

3.08 Solving linear inequalities

Worksheet
Interpret inequalities
1

Write the following sentences using mathematical symbols:

a

n is greater than -17.

b

n is less than -10.

c

w is less than -\dfrac{2}{3}.

d

y is greater than or equal to -12.

e

The product of 6 and x is less than or equal to - 42.

f

The sum of 5 and the product of -4 and x is greater than or equal to 20.

2

Write the following inequalities in words:

a
p \lt -9
b
f \gt -14
c
m \leq -23
d
-a \geq 88
Solve inequalities
3

State the largest integer value x can have if x \leq - 2.

4

State whether the following are solutions of k \leq 15:

a
k = 14
b
k = - 15
c
k = 15
d
k = 16
5

Consider the inequality: 12 - y \gt 10.

a

Find the value of the left-hand side of the inequality when y = 0.

b

Is y = 0 a solution of 12 - y \gt 10?

6

State whether the following are solutions of x + 2 \gt 6:

a
x = 4
b
x = 5
c
x = 3
d
x = - 9
7

Consider the inequality - 2 x \gt 10. Will the direction of the inequality symbol be reversed when solving this inequality? Explain your answer.

8

Sally attempted to solve the inequality - 18 - 6 x \gt 30, but has made a mistake. Her working is shown below:

\begin{aligned} &\text{Step } 1: \quad - 18 - 6 x \gt 30\\ &\text{Step } 2: \quad - 6 x \gt 48\\ &\text{Step } 3: \quad x \gt - 8 \end{aligned}

What was Sally's mistake?

9

Solve the following inequalities:

a
8 x \leq - 48
b
- 9 x \lt 63
c
- 4 x \leq - 16
d
x - 1 \lt 15
e
7 - x \lt 2
f
8 x + 16 \gt 64
g
7 x - 49 \geq 42
h
7 x + 5 \gt x + 35
i
- 3 \left(x + 9\right) \geq - 6
j
-9\left(x+6\right)\geq -27
k
23-3k\leq 2k+3
l
- 4 - 4 x \gt - 7 x + 2
m
\dfrac{x}{- 4} \geq 8
n
2 - \dfrac{1}{2} x \gt 5
o
\dfrac{x}{2} + \dfrac{x}{3} \geq 5
p
\dfrac{x}{9} - \dfrac{x}{7} \lt 0
q
\dfrac{a}{5} + 9 \gt 9
r
91 - 4 k \leq 5 k + 10
10

Write the following sentence using mathematical symbols and solve:

"Negative four groups of x is less than three."

11

Consider the inequality: 6 \left(x + 6\right) \leq 42.

a

Solve the inequality.

b

State whether the following are solutions of: 6 \left(x + 6\right) \leq 42.

i

x = -1

ii

x = 2

iii

x = 0

iv

x = 1

12

Consider the inequality: 30 + 3 x \gt 30.

a

Solve the inequality.

b

State whether the following are solutions of: 30 + 3 x \gt 30.

i

x = 1

ii

x = 0

iii

x = 3

iv

x = 6

13

Consider the inequality: 3 \left( 3 x - 4\right) \geq 15.

a

Solve the inequality.

b

State whether the following are solutions of: 3 \left( 3 x - 4\right) \geq 15.

i

x = 0

ii

x = 3

iii

x = 5

iv

x = - 3

Applications
14

Write the following statement as an inequality in terms of T: The temperature T inside a freezer is always below - 15 \degree \text{C}.

15

Ursula was given \$60 for a birthday present. This present, along with earnings from a Saturday job, are being set aside for a mountain bike. The job pays \$6.50 per hour, and the bike costs \$361.

a

Write and solve an inequality to find the minimum number of hours that Ursula needs to work to be able to buy the mountain bike, where h represents the number of hours worked.

b

If Ursula can only work her job for a whole number of hours, find the minimum number of hours she must work to afford her bike.

16

Ivan wants to save up enough money so that he can buy a new sports equipment set, which costs \$60.00. Ivan has \$21.40 that he has saved from his birthday. In order to make more money, he plans to wash neighbors’ windows for \$4 per window.

a

Let w be the number of windows that Ivan washes. Write and solve an inequality to find the minimum number of windows he needs to wash in order to afford the equipment.

b

Find the minimum whole number of windows that Ivan must wash to be able to afford the equipment.

17

Charlie is saving up to buy a laptop that is selling for \$740. He has \$520 in his bank account and expects a nice sum of money for his birthday next week.

a

If the amount he is to receive for his birthday is represented by x, write an inequality that models the situation where he is able to afford the laptop.

b

Would he have enough to buy the laptop if his parents were to give him \$180 for his birthday?

18

When breeding certain types of fish, it is recommended that the number of female fish is more than triple the number of male fish.

a

If the number of females is represented by f and the number of males is represented by m, write an inequality that represents the recommended relationship between f and m.

b

Find a number of female and male fish that would satisfy the recommendation.

Sign up to access Worksheet
Get full access to our content with a Mathspace account

Outcomes

8.C2.4

Solve inequalities that involve integers, and verify and graph the solutions.

What is Mathspace

About Mathspace