1) ( 1 / ( a² - b² )) * ( ( a - b )² / ( a + b )) = ( a - b ) / ( a + b )²
2) a² + ab = a( a + b )
3) ( ( a - b )/ (a( a + b )) - ( ( a - b )/( a + b )² ) = ( ( a - b )( a + b ) - a( a - b )) /
/ ( a( a + b )² ) = ( a² - b² - a² + ab ) / ( a( a + b )² ) = ( ab - b² ) / ( a( a + b )² ) =
= ( b( a - b )) / ( a( a + b )² )
4) a² + ab = a( a + b )
5) ( b( a - b )) / ( a( a + b )² ) : ( a - b ) / ( a( a + b )) = b / ( a + b )
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a = 0,5
b = - 1
- 1 / ( 0,5 - 1 ) = - 1 / - 0,5 = 2
ОТВЕТ 2