b: 4/5:(-3/5)-7/10 c: 13/7+(-8/7): (-4/5) Pouvez vous detaillez svp ?

b = 4/5 : ( -3/5) - 7/10
b = 4/5 * - 5/3 - 7/10
b = - 20/15 - 7/10
b = - 40/30 - 21/30 = - 61/30

c = 13/7 - 8/7 * - 5/4
c = 13/7 + 40/28
c = 52/28 + 40/28 = 92/28 = 23/7

B: 4/5:(-3/5)-7/10
b  4/5 x -5/3 -7/10
b = -4/3 -7/10
b = -40/30 -21/30
b = -61/30


c: 13/7+(-8/7): (-4/5)
13/7  + ( -8/7 x -5/4)
13/7 + (10/7)
23/7