bonsoir,
f = ( x - 5 ) ( 2 x + 3 ) - x² + 25
f = ( x - 5 ) ( 2 x + 3 ) + ( x - 5 ) ( x + 5 )
f = ( x - 5 ) ( 2 x + 3 + x + 5 )
f = ( x - 5 ) ( 3 x + 8 )
g = ( 6 x - 10 ) ( 4 - x ) - ( 5 - 3 x )²
g = - 2 ( - 3 x + 5 ) ( 4 - x ) - ( 5 - 3 x )²
g = ( - 3 x + 5 ) ( - 8 + 2 x - 5 + 3 x )
g = ( - 3 x + 5 ) ( 5 x - 13 )