Download Section 2.6 “Solving Equations Using Multiplication and Division”

Do Now 10/14/09
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Take out HW from last night.
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Copy HW in your planner.
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Punchline worksheet 38
Text page 99, #8 – 32 evens
In your journal, explain how you think you would solve
the following equations. Then solve.
2x  14
x
 20
5
Homework
Punchline worksheet 38
“What Do Opticians, Optometrists,
and Opthamologists Have In
Common?”
THEY ALL WENT TO EYE SCHOOL
Objective
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SWBAT use multiplication and division
to solve equations
Equation
mathematical sentence
with an equal sign
Like a scale,
both sides
must be balanced
Equation
x + 7 = 10
Left side
‘x’ has to be 3 in order
to make the equation
balanced.
Like a scale, the left
side and right side must
be the same in order to
be balanced!
Right side
Section 2.6 “Solving Equations Using
Multiplication and Division”
How can you get the “unknown” by itself?
-2y = 28
“Undo” the operation by using the INVERSE
operation to both sides of the equation.
Solving a Multiplication Equation
-2y = 28
-2
-2
y = -14
“Undo”
multiplication
by dividing
both sides of the
equation
Check Your Work! y = -14
-2y = 28
-2(-14) = 28
Are both sides equal?
Try It Out
1). -7t = 63
2). -144 = 12d
3). 10x = 5
1). t = -9
-7(-9) = 63
2). d = -12
-144 = 12(-12)
3). x = ½
10(½) = 5
Solving a Division Equation
5· j = -7 · 5
5
j = -35
“Undo”
division by
multiplying
both
sides of the
equation
Check Your Work!
j = -7
5
-35 = -7
5
j = -35
Are both sides equal?
Try It Out
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1). r ÷ 8 = -2
2). v = 8
4
3). -9 = a
5
1). r = -16
-16 ÷ 8 = -2
2). v = 32
32 = 8
4
3). a = -45
-9 = -45
5
Find the width of the rectangle.
x
2x = 38 cm²
2 Area = 38 cm²
9z = 27 m²
x = 19 cm
9
z Area = 27 m²
z=3m
Homework
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Text page 99, #8 – 32 evens
WAR!!!
Using your boards solve the
equations as fast as possible.
If your number is called … you
are at WAR!!