Solving Two-Step Solving Two-Step EquationsEquations

Integer ReviewInteger Review Adding and Subtracting Adding and Subtracting

Think MoneyThink MoneyThink TemperatureThink Temperature

-18 + 13 -11 + 19 41 + (-63)

-5-5 8 8 -22-22

Integer ReviewInteger Review Multiplication/Division Multiplication/Division

++

-- - -

-4(11) -8(-6) 6(-5) -44 48 -30

Think Christmas

Tree

Brain BreakBrain Break

Why you should like equationsWhy you should like equations

To solve an equation, you “undo” or do the To solve an equation, you “undo” or do the opposite of what is told to you.opposite of what is told to you.

3x + 7 = 19The problem says, multiply by 3, add 7You being in middle school say “NO WAY”

subtract 7, divide by 3

Opposite and backwards – just like most 14 year olds

Solving Two-Step Solving Two-Step Equations:Equations:

It is called a two-step equation because it takes two steps to

solve it“Undo” the

addition first

The variable is by itself so the problem is completed

2x + 5 = 19

- 5 - 52x = 14

“Undo” the implied multiplication last

2x = 142 2

x = 7

Solving Two-Step Solving Two-Step Equations:Equations:It is called a two-step

equation because it takes two steps to

solve it“Undo” the +3 first

The variable is by itself so the problem is completed

3 – a = 9 7

-3 - 3

-a = 67

“Undo” the implied division last7(-a) =(6) 7

7 -a = 42

a = -42

Solving Two-Step Equations Solving Two-Step Equations Practice:Practice:

4 + 2y = 10 x – 6 = -12 8- 4 - 4

2y = 6

2y = 6 2 2

y = 3

+6 = +6

x = -68

8(x) = (-6) 8 8

x = -48

Solving Two-Step Equations Solving Two-Step Equations Practice:Practice:

-10 + 2y = 12 9z + 4 – 8 = 5.4 5 +10 +10

2y = 22

2y = 22 2 2

x = 11

+8 +8

9z + 4 = 13.4 5 Multiply by 5

9z + 4 = 67Add 49z = 63Divide by 9

z = 7

Solving Two-Step Solving Two-Step EquationsEquations Practice: Practice:

4( ) ( )4

17 – x = -40

-17 = -17 -x = -57

x = 57

+ 3 +3

0.2y = 15

0.2y = 15 0.2 0.2

y = 75

17 – x = -10 4

0.2y – 3 = 12

Find a Match ActivityFind a Match Activity

You and your 11 o’clock partner will need to: Obtain a “find a match” paper Work out the problems on the paper Go around the room to find the words that match

the numbers you have

Homework: worksheet 100

ON YOUR OWN!