1) ( 8а/( а^2 - b^2)) + 3/( b - a ) - 4/( a + b ) = ( 8a - 3( a + b ) - 4( a - b )) / ( a^2 - b^2 ) = ( 8a - 3a - 3b - 4a + 4b )/( a^2 - b^2 ) = ( a + b ) / ( ( a - b )( a + b )) = 1 / ( a - b )
2) ( ( 1/( a - b )) : ( 1/( 5a - 5b )) = (( 1/( a - b )) •( 5( a - b )) = 1/5 = 0,2
Ответ 0,2