bonjour
A = 2/3 - ( 7/3 x 8 ) / 21
A = 2/3 - ( 56/3 : 21 )
A = 2/3 - ( 56/3 x 1/21 ) = 2/3 - 56/63
A = 2/3 - 8/9
A = 6/9 - 8/9
A = - 2/9
B =[ ( 3/4 - 5 /6) x 3 ] sur 2
B = [ ( 9/12 - 10/12 ) x 3] sur 2
B =( - 1/12 x 3)sur 2
B = - 3 /12 : 2
B = - 1/4 x 1/2
B = - 1/8
C = [ ( 24/15 + 35/25 ) x 20 ] / 33
C = [ 120/75 + 105/75) x 20 ] / 33
C = ( 225/75 x 20 ) / 33
C = 4 500 /75 : 33
C = 60/33 = 20/11
D = ( 5/6 - 5/4 ) : ( 1/2 + 2/3 )
D = ( 10/12 - 15/12 ) : ( 3/6 + 4/6 )
D = - 5/12 : 7/6
D = - 5/12 x 6/7
D = - 30/84 = - 5/14
