Sagot :
a = 6/6-1/6+4/6 = 9/6 = 3/2
b = 20/12-14/12+9/12 = 29/12-14/12 = 15/12 = 5/4
c = 35/14-36/14-5/14 = 35/14 - 41/14 = - 6/14 = -3/7
d = 2/21 x (10/4 - 3/4) = 2/21 x 7/4 = 14/ 84 = 1/6
A=3-1/6+2/3=18/6-1/6+4/6=21/6=7/2
B= 40/24-28/24+18/24=20/24=5/4
C= 35/14-36/14-5/14=-6/14=-3/7
D=(2/21*5/2)-(2/21*3/4)=10/42-6/84=20/84-6/84=14/84=1/6
voila ;)