bonjour
( x - 2 ) ( x + 2 ) + ( x - 2 ) ( x + 7 )
= ( x - 2 ) ( x + 2 + x + 7 )
= ( x - 2 ) ( 2 x+9 )
( 2 x + 1 ) ( 1 - x ) + ( 2 x + 1 ) ( 3 - 2 x )
= ( 2 x +1 ) ( 1 - x + 3 - 2 x )
= ( 2 x + 1 ) ( - 3 x + 4 )
x ( x + 2 ) + ( x - 4 ) x
= x ( x + 2 + x - 4 )
= x ( 2 x - 2 )
continue
