bonjour
A( x) = 8 / x + x / ( x + 2 )
A (x) = ( 8 x + 2 ) / x ( x + 2) + x² / x ( x + 2 )
A ( x) = ( 8 x + 16 + x²) / ( x ( x + 2 )
A ( x) = ( x + 4)² / x ( x + 2 )
B (x) = 1 - 4 / ( x - 1 )²
B (x) = ( x - 1 )² / ( x - 1 )² - 4 / ( x - 1 )²
B (x) = ( x - 1 )² - 4 / ( x - 1 ) ²
B (x) = ( x - 1 - 2 ) ( x - 1 + 2 ) / ( x + 1 )²
B (x) = ( x - 3 ) ( x + 1 ) / ( x + 1 )²