\"\"

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\"\"

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The equation is  \"\"

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According to Subtraction Property of equality: If \"\" then, \"\".\"\"   (Subtract cd from each side)

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\"\"   (Distributive property:\"\")             \"\"            (Additive inverse property: \"\")

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\"\"                      (Additive identity proparty:\"\")

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\"\"

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According to Subtraction Property of equality: If \"\" then, \"\".

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\"\"        (Subtract z from each side)

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\"\"            (Additive inverse property:\"\")

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\"\"                      (Additive identity proparty:\"\")

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\"\"                    (Distributive property:\"\") 

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\"\"            (Divide each side by 10-d)

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\"\"                          (Cancel common terms)

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\"\"

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Verify:

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To check the solution, substitute \"\" in original equation

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\"\" \ \

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\"\"                    (Cancel by the common terms)

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\"\"                        (Additive inverse property: \"\")

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\"\"                                     (Additive identity proparty:\"\")

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Compare the values, the equation is true.

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\"\"

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The value of a is \"\".