NO Mtn math today.
• Quiz
• Clear your desk of everything. You only
need a calculator.
Variables, Expressions, and
Equations
GLE 0506.3.4 Solve single-step linear equations and
inequalities.
Checks 0506.3.2 Use variables appropriately to
represent numbers whose values are not yet known.
Checks 0506.3.3 Solve single-step linear equations
using inverse operations.
0505.3.1 Evaluate an expression by substituting a
number for the variable or variables in the problem.
Objective:
Understand and be
able to solve
expressions and
equations.
What is a variable???
Discuss with a neighbor
Variable is…. A letter or symbol that
represents an unknown number/amount.
Examples: a , C, x, N,
,
These are variables
A = # , C = #,
X = #,r = #, n = #
=#
=#
These are not
A,
C,
n
3, 10, 75, 8,
12, 1, 0
Reading and Writing Algebraic Expressions
+
plus
sum
more than
increased
by
total
in all
added to
-
minus
difference
less than
subtract
decreased
by
Take away
Subtracted
from
x
times
product
multiplied
each
of

divided
quotient
divided by
Other ways to show Other ways to show
division:
multiplication :
5x6
5(6)
5·6
12 ÷ 6
12/6
5
When we evaluate algebraic expressions, we are
substituting a number in place of variable, then solving
for an answer
Evaluate each expression
when a = 13
1)a + 3
2)17 – a
6
When we evaluate algebraic expressions, we are
substituting a number in place of variable, then solving
for an answer
Evaluate each expression
when a = 13
1)a + 3
13 + 3
16
2) 17 – a
17 – 13
4
7
You try to evaluate the following when
d=3
• 1) 25 – d
• 2) d + 21
You try to evaluate the following
expression when d = 3
1) 25 – d
25 – 3
25 – 3 = 22
2) d + 21
3 + 21
3 + 21 = 24
An Equation is a complete sentence that
is either true or false
= shows that each side has the same
value
examples:
x + 7 = 14
7 + 7 = 14
14 = 14
47 = 50 – 3
y – 6 = 13
10
Brainpop-Equations
• http://www.brainpop.com/math/algebra
/equationswithvariables/
Next slides 11-18 are 13 questions for
review (around the room if you have time)
•
Then, equations adding and
subtracting.
- WB page 233 #1-5
- Practice Workbook page 234
- HW- Worksheet #1
Determine if the following are
expressions or equations:
1)7x
2)(6-3) – 1 = 2
3)14 = 7(2)
4)X + 9 = 13
5)12 – 5
13
6. Which algebraic expression represents
the phrase: fifteen times a number,
plus 3.
A. 15(x – 3)
B. 15(x) +15(3)
C. 15x + 3
D. 15 + 3x
7. Which expression represents the phrase: 7
more than a number, times 4?
A.
B.
C.
D.
(7 – n) x 4
(n + 7) x 4
7 + 4n
4n + 7
8. Write the
expression for n = 9
• 42.3 – n
A.
B.
C.
D.
40.6
34.3
33.3
31.3
9.Solve:
If N = 2,
then 2N =
A. 4
B. 2
C. 3
D. 5
10. Alex scored 117 more points than Seth when
they went bowling. The math expression n + 117
represents this sentence. What does "n" stand for
in this math expression?
A.
B.
C.
D.
Alex and Seth's score together
Seth's score
neither Alex's or Seth's score
Alex's score
11. Megan and Karen each played 5 games. In those 5
Megan had g goals and Karen had 2 less than Megan.
• Write an algebraic expression for the
number of goals Karen had at the end
of the 5 games.
A. g – 2
B. g + 2
C. g x 2
12. Your monthly internet bill is $43 plus $5.50 for each
optional service. Which expression represents a bill
including s optional services?
A.$43 x $5.50 x s
B.$43 + $5.50 x s
C.$43 + $5.50 + s
D.$43 x s + $5.50
13. The soccer field is 10 yards wider than the football
field. Evaluate f + 10 for f = 50 yards to find out how long
the soccer field is if the football field is 50 yards wide.
A.80 yards
B.70 yards
C.60 yards
D.50 yards
Determine if the following are
expressions or equations:
1)7x
• 1) expression
2)(6-3) – 1 = 2 • 2) equation
3)14 = 7(2)
• 3) equation
4)X + 9 = 13
• 4) equation
5)12 – 5
• 5) expression
How could you tell the difference between the two?
21
6.C
7.B
8.C
9.A
10.B
11.A
12.B
13.C
Equations
Objective:
GLE
0506.3.4 Solve single-step
Understand
and be linear
equations and inequalities.
to Use
solve
Checksable
0506.3.2
variables appropriately
to represent
numbers
whose
values
are
not
equations
using
yet known.
multiplication
and linear
Checks
0506.3.3 Solve single-step
equations using inverse operations.
division.
Tuesday
•
•
•
•
http://www.pearsonsuccessnet.com/s
npapp/learn/navigateIDP.do?method=
vlo&internalId=130511100000141 –
video 15-00
Textbook page 378 #1-6 together
For practice: Workbook page 236
with a partner
HW- worksheet #2 mult/div