2.1 Solving Equations by Adding and Subtracting Algebra 1 Book Pg. 77

Warm Ups Evaluate

40%

3

40%

4 1 3 A.

B.

C.

 2 3 3 2 3 2 6

20% A.

B.

C.

What is the Additive Inverse?

1. 8 2. 6 3.

1 2 4. - 5 5.

 2 3

Evaluate each Expression • For (a = 3) and (b = - 2) 1. a + 5 2. 12 - b

Objective • Solve one-step equations in one variable by using addition, subtraction, multiplication, or division

Vocabulary

•

Equation

– A mathematical statement that two expressions are equal •

Solution of an Equation

– Value of the variable that makes the statement true

Finding Solutions • In order to find solutions we must,

Isolate the Variable

• A variable is ISOLATED if it appears by itself on one side of the equation and not at all on the other side of the equation

• • • • • • • • Solving Expressions In order to solve any mathematical expression we must always follow the order of operations

PEMDAS

P – Please Parentheses E – Excuse Exponents M – My Multiply D – Dear Divide A – Aunt Add S – Sally Subtract

• • Solving Variable Equations In order to Isolate the variable, we sometimes need to move terms in the equations

REMEMBER

– When combining terms on the same side of the EQUAL SIGN, you keep the SAME sign of the terms and just add them together

x

5 2

y x

3

y

 – – We only use the OPPOSITE sign when we have to cross the equal sign This is because we are taking it off one side and adding it to the other

Angles 4 and 5 are called ?

3 1 4 2 7 5 8 6

25% 25% 25% 25%

A. Vertical B. Corresponding C. Linear Pair D. Alternate Interior

Ve rti ca l Co rre sp on din g Lin ea r P air Al ter na te Int er ior

7 5 8 6 Angles 1 and 7 are?

3 1 4 2 A. Congruent B. Complimentary C. Supplementary

Co ng ru en t 0% 0% Co mp limen ta ry 0% Su pp leme nt ar y

Moving Terms • • First look at the problem and decide which operations you have and do you have to move them across an equal sign If you do we must do the Inverse Operation in reverse order of the Order of Operations

Operation

Addition Subtraction Multiplication Division

Inverse Operations Inverse Operation

Subtraction Addition Division Multiplication

2 5 1 5 Examples

x

 10  4

b

2 Examples

x

9

When multiplying and dividing • Rules (+)(+) = (+) (+)(-) = (-)                                                        

m

 1.5

3 Examples

k

 5

5 9

v

 35 Examples 7

x

 56

Homework • Pg. 80, 21 – 47 EEO • Pg. 87, 21 – 35 EEO • EEO (every other odd)