Solving Equations Using Multiplication and Division
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Transcript Solving Equations Using Multiplication and Division
Do Now 10/17/11
Take out HW from Friday.
Copy HW in your planner.
Punchline worksheet #38
Text p. 74, #4-6, 14-19, 22-34 evens, 43, 44, 48, & 49
Quiz on equations Friday.
Be ready to copy Problem of the Week #6.
Homework
Punchline worksheet 38
“What Do Opticians, Optometrists,
and Opthamologists Have In
Common?”
THEY ALL WENT TO EYE SCHOOL
Objective
SWBAT use multiplication and division
to solve equations
Equation
mathematical sentence
with an equal sign
Like a scale,
both sides
must be balanced
Equation
2x = 10
Left side
‘x’ has to be 5 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 2-5 “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
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
24
Homework
Text p. 74, #4-6, 14-19, 22-34 evens, 43, 44, 48, & 49
WAR!!!
Using your boards solve the
equations as fast as possible.
If your number is called … you
are at WAR!!