1)
= ( 3,17 - 1,17)^2 / ( 6,75 - 3,25) * ( 6,75 + 3,25 ) =
= 2 ^2 / ( 3,5 * 10 ) =
= 4 / 35
Ответ 4/35
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2)
а) ( А - 1)*( A + 3) - ( A + 1)^2 = A^2 + 3A - A - 3 - ( A^2 + 2A + 1 ) =
= A^2 + 2A - 3 - A^2 - 2A - 1 = ( - 4 )
б) ( X - Y)*( X + Y)*( X^2 + Y^2 ) = ( X^2 - Y^2)*( X^2 + Y^2) = X^4 - Y^4
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3)
1) X / ( 3 * ( X - 2Y)) + Y / 2Y - X = ( X - 3Y) / ( 3 * ( X - 2Y)
2) [ ( X - 2Y) / ( X - 3Y) ] * [ ( X - 3Y) / ( 3 * ( X - 2Y) ] = 1/3
Ответ 1/3