Bonjour,
A)
3-2/3 = 9/3 - 2/3 = 7/3
4/3 * 7 = 28/3
(7/3) / (28/3) = 7/3 * 3/28 = 7*28 =1/4
b)
(2/3)/ (5/6) = 2/3 * 6/5 = 12/ 15 = 4/5
4/5 -2/5 = 2/5
c)
-3/4 +1/2 = -3/4 + 2/4 = -1/4
2/5 -5/2 = 4/10 - 25/10 = - 21/10
(-1/4) /( -21/10) = -1/4 * -10/21
= 10/ 84 = 5/42