Réponse :
bonjour,
3x - ( - 2x - 1) = 3x +2x + 1 = 5x -1
-( 2x² -2 ) + ( x - 2 ) - ( 2 - x ) = -2x² +2 + x - 2 -2 + x = -2x² -2 +2x = -2x² + 2x - 2
3x - ( 2x² +1 -8x ) - ( 3x -2x² + 7 ) = 3x - 2x² -1 +8x -3x +2x² -7 = 8x - 8
3 ( x - 2 ) - 3 ( 2x - 1 ) = 3x -6 - 6x +3 = -3x -3
-2 [ 2 - ( 1 - x ) ] = -2 ×( 2-1 + x) = -2 ( 1 + x ) = -2 -2x
( -2 + 3x ) ( -2 ) - ( 6x + 2 ) = 4 -6x - 6x - 2 = -12x +2
voila :)
