Objective
The student will be able to:
solve open sentences by performing
arithmetic operations.
SOL: A.1
Designed by Skip Tyler, Varina High School and Nicole Kessinger, Deep Run High School
A Variable Expression is a group
of numbers, variables, and
operations. (No equal sign)
Examples
12m - 42
3x + 2
An Equation is a mathematical
sentence that contains an equal
sign (=).
Examples
2+4=6
3x + 2 = 11
A sentence that has the symbol
,  , , or  is called an
inequality.
Examples
3a  43
x + 7  -27
Expression, equation, or inequality?
13x + 14y = 30
1. Expression
2. Equation
3. Inequality
Answer Now
Expression, equation, or inequality?
-2x - 4
1. Expression
2. Equation
3. Inequality
Answer Now
Expression, equation, or inequality?
4b  21
1. Expression
2. Equation
3. Inequality
Answer Now
Expression, equation, or inequality?
10a - 22 = -92
1. Expression
2. Equation
3. Inequality
Answer Now
Expression, equation, or inequality?
-7k  -35
1. Expression
2. Equation
3. Inequality
Answer Now
Sometimes you can solve an equation
by applying the order of operations.
4+5•2 =m
8-1
2=m
2 is the solution. It is a number that
replaces the variable (m) and makes
the equation true.
The pay (P) at a certain job is calculated by multiplying the
base pay (b) by the number of hours worked (h). If an
employee works overtime (more than 40 hours in 1 week),
the formula is P = 40b + 1.5b(h - 40). If Jamaal had base
pay of $12.50/hr. and worked 46 hours, what would be his
pay for the week?
1.
2.
3.
4.
$525.00
$575.00
$597.00
$612.50
Answer Now
If a side of the square shown
has length 20, what is the area
of the circle (A=πr2)?
1.
2.
3.
4.
1,257
314
125.6
68.8
Answer Now
A set is a collection of objects or
numbers.
Each object in the set is called an element.
Example
Coins = {Penny, Nickel, Dime, Quarter,
Half Dollar, Dollar}
Coins is the set & Dime is an element of
the set of Coins.
Replacement Set: a set of numbers
from which a number may be
chosen to take the place of the
variable (All the numbers may not
make the equation/inequality true.)
Solution Set: the set of all
replacements for the variable that
make the equation/inequality
TRUE
Given 8 - x < 7, find the solution set if
the replacement set is {0, 2, 4, 6, 8}.
Replace the variable (x) with each element in the
replacement set and solve.
8-0<7
8<7
False
8-2<7
6<7
True
8-4<7
4<7
True
8-6<7
2<7
True
8-8<7
0<7
True
The solution set is {2, 4, 6, 8}.
Given 5 = 10 - y, find the solution
set if the replacement set is
{1, 2, 3, 4}.
1.
2.
3.
4.
5.
{1}
{1,2}
{1,2,3}
{1,2,3,4}
Null Set
Answer Now
Given 5 = 10 - y, find the solution
set if the replacement set is
{1, 2, 3, 4}.
5 = 10 - 1
5=9
False
5 = 10 - 2
5=8
False
5 = 10 - 3
5=7
False
5 = 10 - 4
5=6
False
None of these are true so the solution set is null
set.
Null set is a set with no elements.
Bonus Question!
What is the area of the
shaded region?
1.
2.
3.
4.
10.37
10.75
42.52
127.5
Answer Now