Post on 19-Jan-2016
transcript
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Small Square
Value = 1
Rectangle
x
1
1
1
Value = x
Large Square
x
x
Value = x2
Algebra Tiles
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Small Square
Value = -1
Rectangle
-x
-1
1
1
Value = -x
Large Square
-x
x
Value = -x2
Algebra Tiles
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We are going to use Algebra Tiles to solve algebraic equations.
Algebra Tiles
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An Equation is like a balance scale. Everything must be equal on both sides.
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What you do to one side of an equation, you must do to the other side to keep it
balanced.
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4x-2=2x+3
What Equation Is This?
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-3x+1=2x+3
What Equation Is This?
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-3x+2= x-1
What Equation Is This?
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-3x-2= -x-1
What Equation Is This?
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#18
+ + x
x x
–
Move the smaller
number of x’s to one side
2 = 2x - 2 +2 +2
4 = 2x
=
2x + 2 = 4x – 2 x
x
2x + 2 = 4x - 2 -2x -2x
x –
+ + ++
2 22 = x
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Then you will draw the problem.Then you will write the algebra equation, solve and show the check.
It is important to see the problem on your balance scale with the algebra tiles 1st. I want to make sure you understand it conceptually before doing the algebra!
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Show me problem #1 2x + 1 = x + 3
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Take 1x away from both sides.
Draw this on your homework paper
x = 2Take 1 away from both sides.
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Draw problem #1 2x + 1 = x + 3
+x + += +
Take 1x away from both sides.
x xTake 1 away from both sides.
2x + 1 = x + 3 -x -x
x + 1 = 3
2(2) + 1 = 2 + 3
-1 -1 x = 2
4 + 1 = 5 5 = 5
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Show me problem #2 3x + 2 = x + 8
=
Take 1x away from both sides.
Draw this on your homework paper
x = 3Take 2 away from both sides.
Divide both sides by 2.
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Draw Problem #2 3x + 2 = x + 8
+ + += +Take 1x away from both sides.
Take 2 away from both sides.
+ + + +++
Divide both sides by 2. 3x + 2 = x + 8
-x -x2x + 2 = 8
-2 -2 2x = 6
2 2 x = 3
3(3)+2= 3 + 89+2=1
1 11=11
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Show me problem #3 3x - 5 = 4
=
Add 5 to both sides.
Draw this on your homework paper
x = 3Take away the zeros
Divide both sides by 3.
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Draw problem #3 3x - 5 = 4- + +
=Add 5 to both sidesTake away the zeros
- + +
Divide both sides by 3.
--
-
+ + +++
+++
+ +
3x - 5 = 4 +5 +5
3x = 9 3 3
x = 3
3(3) - 5 = 4 9 - 5 = 4 4 = 4
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Show me problem #4 2x - 1 = 3x
=
Take 2x away from both sides.
Draw this on your homework paper
x = -1
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Draw problem #4 2x - 1 = 3x
- =Take 2x away from both sides.
2x - 1 = 3x -2x -
2x - 1 = x
2(-1) - 1 = 3(-1)-2 - 1 = -3
-3 = -3
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Show me problem #5 4x + 1 = 3x - 1
=
Draw this on your homework paper
Take away 3x from both sides.
Add -1 to both sides.
Take away the zeros
x = -2
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Draw Problem #5 4x + 1 = 3x - 1 + = _
Take away 3x from both sides.Add -1 to both sides.
Take away the zeros
4x + 1 = 3x – 1 -3x -3x x + 1 = -1 -1 -1 x =
-2
4(-2)+1= 3(-2) -1 -8+1= -6 –
1 -7 = -7
_ _