(3/4+0.25-1целая5/24): (2целых3/4-4целых1/2-0.75): (-4целых7/12)

1)3/4+0.25=3/4+25/100=25*3/100+25/100=75/100+25/100=100/100=1
2)1-1 5/24=1/1-29/24=24/24-29/24=-5/24
3)2 3/4-4 1/2=11/4-9/2=11/4-9*2/4=11/4-18/4=-7/4=-1 3/4=-1.75
4)-1.75-0.75=-2.5
5)-5/24:(-2,5)=5/24:25/10=5/24*10/25=1/12*5/5=5/60=1/12
6)1/12:(-4 7/12)=1/12:(-55/12)=1/12*(-12/55)=-1/55

(3/4 + 0.25 - 1 5/24) : (2 3/4 - 4 1/2 - 0.75) : (-4 7/12) = -2/25 (или -0,08),

1) 3/4 + 0.25 - 1 5/24 = 3/4 + 1/4 - 29/24= 1/24 + 6/24 - 29/24 = -22/24 = -11/12,
2) 2 3/4 - 4 1/2 - 0.75 = 11/4 - 9/2 - 3/4 = 11/4 - 18/4 - 3/4 = -10/4 = -2 1/2,
3) -11/12 : (-2 1/2) = 11/12 : 5/2 = 11/12 * 2/5 = 11/30,
4) 11/30 : (-4 7/12) = -11/30 : 55/12 = -11/30 * 12/55 = -2/25 (или -0,08)