Bonsoir,
A = 5/- 51 x - 34/15
A = 170/765
A = (85 x 2) / (85 x 9)
A = 2/9
B = 45/21 x - 28/- 55 x 11/- 27
B = 1 260/1 155 x - 11/27
B = - 13 860/31 185
B = (3 465 x - 4) / (3 465 x 9)
B = - 4/9
C = 6/7 - 3/28
C = - 18/196
C = (2 x - 9) / (2 x 98)
C = - 9/98.