(1-3/4)*(5/4-3/4)*14*(1/2+1/3+1/4)*1/3*6/7-1/7*3/4=-39/560
1) 1-3/4= 4/4-3/4=1/4=0,25
2) 5/4-3/4=2/4=0,5
3) 1/2+1/3+1/4=6/12+4/12+3/12=13/12=1,1/12
4) 0,25*0,5=0,125
5) 0,125*14=1,75
6)1,75*1,1/2=175/100*11/10=77/40=1,37/40=1,925
7) 1,925*1/3=1925/1000*1/3=77/120
8) 77/120*6/7=1/20=0,05
9) 0,05-1/7=5/100-1/7=35/700-100/700=-65/700=-13/140
10) -13/140*3/4=-39/560