A = 3 ( 2x - 6 ) - ( 3 - 5x ) B = ( 5 - 2y ) - ( -3y +7) C = 4 ( 6 + z ) + ( z - 3 ) ( 2 - z ) D = ( 2t - 5 ) ( 3t + 2 ) - ( t exposant 2 + 6 )