Sagot :
B= 7/4 + 25/20. B= 7*5/4*5 + 25/20= 35/20 + 25/20=60/20. Ensuite tu prends exemple
C = 35/49 - 6/14
C = 5/7 - 3/7
C = 5-3/7
C = 2/7
D = 21/18 - 14/12
D = 7/6 - 7/6
D = 0