1) 29*0.45+0.45*11=0,45*(29+11)=0,45*40=18
2)4.07-5.49+8.93-1.51=(4,07+8,93)-(5,49+1,51)=13-7=6
3)-11.401-23.17+4.401-10.83=(-11,401+4,401)-(23,17+10,83)=-7-34=-41
4) (51,8+44.3+48.2-24.3)* 1/3
=[(51,8+48,2)+(44,3-24,3)]*1/3=(100+20)*1/3=
=120*1/3=40