\"\"

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The equations are

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\"\"                    (Equation 1)

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\"\"                                (Equation 2)

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Since \"\"

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Rewrite the second equation for x.

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\"\"

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\"\"

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Apply subtraction property of equality: Subtract 2y from each side.

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\"\"

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\"\"               (Apply additive inverse property: \"\")

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\"\"                     (Apply additive identity property: \"\")\"\"

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Now Substitute  \"\" for x in either equation to find the value of y.

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\"\"                     (Equation 1)

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\"\"          (Replace \"\")

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Distribute terms using distributive property: \"\".

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\"\"

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\"\"             (Multiply: \"\")

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\"\"                       (Subtract: \"\")\"\"

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Apply subtraction property of equality: Subtract 20 from each side.

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\"\"

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Apply commutative property of addition: \"\".

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\"\"

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\"\"        (Apply additive inverse property: \"\")

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\"\"           (Aplly additive identity property: \"\")

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\"\"                    (Subtract: \"\")\"\"

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Apply division property of equality: Divide each side by 70.

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\"\"

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\"\"                           (Cancel common terms)

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\"\"            (Multiply each side by negative one)

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\"\"                                  (Product of two same signs is positive)\"\"

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Now  \"\"

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\"\"                     (Replace y by 1)

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\"\"                           (Apply multiplicative identity property: \"\") \ \

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\"\"                             (Subtract: \"\")

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The solution is \"\"\"\"

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The solution is \"\".