2P ( X - 7 ) - P ( 2X ) = ?
P ( X ) = X - 3
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P ( X - 7 ) = X - 3 - 7 = X - 10
2P ( X - 7 ) = 2X - 20
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P ( 2X ) = 2 * ( X - 3 ) = 2X - 6
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2X - 20 - ( 2X - 6 ) = 2X - 20 - 2X + 6 = - 20 + 6 = - 14
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Ответ ( - 14 )