bonsoir
(2x-5)(x+6)+(5-2x)(4x+8)
= ( 2 x - 5 ) ( x + 6 ) - 1 ( 5 - 2 x ) ( 4 x + 8 )
= ( 2 x - 5 ) ( x + 6 - 4 x - 8 )
= ( 2 x - 5 ) ( - 3 x - 2 )
