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

These are variables These are not

A = # , C = #, X = #,r = #, n = #

= # = #

A, C, n

3, 10, 75, 8, 12, 1, 0

Variable is…. A letter or symbol that represents an unknown number/amount.

Examples: a , C, x, N, ,

+ - x

plussummore thanincreased bytotalin alladded to

minusdifferenceless thansubtractdecreased byTake awaySubtracted from

timesproductmultipliedeachof

dividedquotientdivided by

Other ways to show

multiplication : 5 x 6 5(6) 5 · 6

Other ways to showdivision:

12 ÷ 6 12/6

Reading and Writing Algebraic Expressions

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 =

131)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 + 313 + 3

162) 17 – a 17 – 13

47

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 – d25 – 3

25 – 3 = 22

2) d + 213 + 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 47 = 50 – 3 7 + 7 = 14 y – 6 = 13 14 = 14

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)7x2)(6-3) – 1 =

23)14 = 7(2)4)X + 9 = 135)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 + 3D. 15 + 3x

7. Which expression represents the phrase: 7 more than a number, times 4?

A. (7 – n) x 4B. (n + 7) x 4C. 7 + 4nD. 4n + 7

8. Write the expression for n = 9•42.3 – n

A. 40.6B. 34.3C. 33.3D. 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. Alex and Seth's score together B. Seth's score C. neither Alex's or Seth's score D. 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 – 2B. g + 2C. 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 sB.$43 + $5.50 x sC.$43 + $5.50 + sD.$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 yardsB.70 yardsC.60 yardsD.50 yards

Determine if the following are expressions or equations:1)7x2)(6-3) – 1 =

23)14 = 7(2)4)X + 9 = 135)12 – 5

•1) expression•2) equation•3) equation•4) equation•5) expression

How could you tell the difference between the two?21

6.C7.B8.C9.A10.B11.A12.B13.C

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.

Objective: Understand and be able to solve equations using multiplication and division.

Tuesday

• http://www.pearsonsuccessnet.com/snpapp/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