P1253037255KawOS

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Using the Inverse Operation
What is the inverse of multiplication?
Division
So we can use division to solve problems that
involve multiplication and multiplication to
solve problems with division
Example Isolate the variable
Do the inverse so divide by 3
Now check your answer!!
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Checking your answer
X 4 so plug it back into the original problem
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More examples
The opposite of Division is Multiplications so x
by 2
Remember what you do to one side you have to do
to the other
The two cancel so we are left with
Check your answer!!
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Try these
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Multiplying by the Reciprocal
So multiply both sides by the reciprocal
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Try this one
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Whenever we isolate a variable we are using the
properties of equality
Addition property of equality If a b then a
c bc Subtraction Property of equality If ab
then a c b - c Multiplication Property of
equality If ab then ac bc Division property of
equality If ab then a?c b ? c
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What does it mean to be Similar?
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• Similar figures are figures that have the same
  shape, but not necessarily the same size.
• Imagine that you have reduced or enlarged a
  figure in a photocopy machine - the figure has
  the same shape, but not the same size.

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Corresponding Sides Angles
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Ratios
We can use ratios as a way to compare
corresponding sides For example
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Using ratios to find the missing Side
If two figures are similar their ratios are equal
So if I look at the last example
so
Now put in the numbers and using inverse
operations to solve
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Now Solve for X
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Example 1
Find the value for Y
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Example 2