Объяснение:
1 . а) (16−b)/(4√b−b) = [ (4 - √b)(4 + √b)]/√b(4 - √b) = (4 + √b)/√b =4/√b + 1 ;
б ) (m+5√m)/(m−25) = √m(√m + 5)/[ (√m - 5)(√m + 5) ] = √m/( √m - 5 ) .
2 . Доведення :
а ) (√3+2)/(2-√3) = [ ( 2 + √3 )² ] /[( 2 -√3)( 2 + √3 )] = (7 + 4√3)/ [ 2² - (√3)²] =
= (7 + 4√3)/(4 - 3 ) = 7 + 4√3 ;
б) (8-√63)/(8+√63) = [ ( 8-√63 )²]/( 8+√63 ) ( 8-√63) = (127 - 16√63 )/[(8²- -(√63)²] = (127 - 16√63 )/( 64 - 63) = 127-16√63 .
Объяснение:
1 . а) (16−b)/(4√b−b) = [ (4 - √b)(4 + √b)]/√b(4 - √b) = (4 + √b)/√b =4/√b + 1 ;
б ) (m+5√m)/(m−25) = √m(√m + 5)/[ (√m - 5)(√m + 5) ] = √m/( √m - 5 ) .
2 . Доведення :
а ) (√3+2)/(2-√3) = [ ( 2 + √3 )² ] /[( 2 -√3)( 2 + √3 )] = (7 + 4√3)/ [ 2² - (√3)²] =
= (7 + 4√3)/(4 - 3 ) = 7 + 4√3 ;
б) (8-√63)/(8+√63) = [ ( 8-√63 )²]/( 8+√63 ) ( 8-√63) = (127 - 16√63 )/[(8²- -(√63)²] = (127 - 16√63 )/( 64 - 63) = 127-16√63 .