caro67000 A = (3/2-1/3)/(3/4+2/3)
A = (9/6 - 2/6)/ (9/12+8/12)
A = 7/6 / 17/12
A = 7/6 * 12/17
A= 14/17

B= 2 + ((2/7)/(5/14))
B = 2 + (2/7*14/5)
B = 2 + 4/5

C =  -3/14 - (3/(7/5)) + 2
C= -3/14 - ( 3*5/7* 2/2) + 28/14
C =  - 3/14 - 30/14 + 28/14
C = -5/14

D = 7/5 + ((8/15)/(2/3))- 19/2
D = 7/5 + ( 8*3/15*2 ) - 19/2
D = 7/5 + 24/30 - 285/30
D = 42/30 +64/30 - 285/30
D = -179/30
D = -5 - 29/30

E =( 3-7/5) / (1-9/10)
E = ( 15/5 - 7/5)/ 1/10
E = 8/5*10
E= 80/5
E = 16

F = 7/ -8 + ((5/6)/4) -1 =
F = - 7/8 + (5/6*1/4) -1
F = -21/24+ 5/24 - 24/24
F = -40/24
F = -10/6
F = -5/3
F = -1 - 2/3