Warm Up Write an example of a equivalent

expression and most simplified expression for each problem below

1.2x + 3y – 20 + 2

2.6y + 5x2 + 39x – 4(x + y)

Evaluate :

3. If a = 3, b = 9, and c = -4 evaluate:

6a2 + 2b - ca

HW Check – 1.2

Solving Equations

EqualityWhat does it mean for two things to be equal?

Are these equal?

=

EqualitiesEquations are statements where two values are EQUAL!

4 + 5 = 9

EquationsWhen you have a variable, our goal is to find the solution that makes the two parts EQUAL.

X + 1 = 5

What is x?

Check the solutionsFor the following determine if the x makes the equation true.

1. X + 3 = 6 for x = 3

2. 4x = 24 for x = 7

3. 2x + 4 = 10 for x = 3

Inverse OperationsInverse operations are operations that “undo” each other.

For example adding and subtracting are inverse operations.

What are another type of inverse operations?

Solving EquationsWhen we solve an equation, we want to get the variable BY ITSELF on one side of the equation!

We can use INVERSE OPERATIONS to do this!

Whatever you do to one side, you must do to the other side to keep things balanced. (think of the = sign as a balance)

Subtracting and Adding to Solve

Use the inverse operation to solve:

Ex: x + 4 = 6 Ex: x – 3 = -6

Try these!Use subtraction to solve:

1. x + 5 = 10

2. w + 6.45 = 3.5

3. 5.2 + y = -10.6

Try these!Use addition to solve:

1. x – 4 = 12

2. z – 2.3 = 3.8

3. y – 5.3 = -15.6

Word ProblemLisa and Derrick went to the mall to sell tickets to

the school play. They separated to cover more area. Combined they had sold 13 tickets. If Lisa sold seven, how many did Derrick sell?

Using Division to SolveWhen x is multiplied by a number we can divide to get x by itself.

EX: 4x = 8

EX: -2x = 16

Using Multiplication to Solve

When x is divided by a number, we can multiply BOTH sides of the equation by the number to get x by itself.

EX: = 7 EX: = 54

x

3

x

Two Step EquationsSo far we have only done one operation to solve… lets try two

When solving two-step Equations:

FIRST: undo what is farthest away from the variable (usually addition or subtraction)

THEN: undo what is left (usually multiplication or division)

Example15x + 3 = 48

Example – 10 = -64

t

Example9g + 11 = 2

When in a FractionUndo the bottom FIRST then the top!

Solving 2 step equationsScavenger Hunt

You will be solving 10 equations

You may start at any problem that you see hanging around the room

When you solve an equation look for a paper that has the answer you just got, then solve the next equation.

No more then 3 people at any one paper!!

Coming up…HW 1.3

QUIZ Friday