(15.6+9.744/2.4)*0.5 =(15.6+4.06)*0.5=19.66*0.5=9.83
2.881/0.43-3.5*0.24 =6.7-0.84=5.86
13.5*0.68/8.5 =9.18/8.5=1.08
43.6-7.6*4.1 =43.6-31.16=12.44
(86.9+667.6)/50.3 =754.5/50.3=15
(73.5+80.5)/(10+12) =154/22=7
(7.8*15+5.1*10+6*5)/ =(117+51+30)/=198/