x=0,039:(0,05×30)=0,039:1,5=0,026
y=0,02+1,53:0,15=0,02+10,2=10,22
z=29,41-14,11=15,3
a) x+y+z= 0,026+10,22+15,3=25,546
b) z-y-z=15,3-10,22-0,026=5,054
c) 2x+3y-z=0,052+30,66-15,3=15,412
d) 100x+2,1y-z=2,6+21,462-15,3=8,762
