Bonjour,
A)
7/3 *8 = 56/3
(56/3)/21 = 56 /(21*3) =56/63 =8/9
2/3 - 8/9 = 6/9 -8/9 = -2/9
B)
3/4 -5/6 = 9/12 -10/12 = -1/12
-1/12 *3 = -3/12 = -1/4
(-1/4) /2 = -1/8
C )
24/15 +35/25 =
24/15 +7/5 = 24/15 +21/15 = 45/15 = 3
3*20 = 60
60/33 = 20/11
D)
5/6 - 5/4 = 10/12 - 15/12 = -5/12
1/2 +2/3 = 3/6 +4/6= 7/6
(-5/12 )/(7/6)
(-5 *6) / (12*7) = -30/ 84 = -15/40 = -3/8
