Răspuns:
a a•20+b•20=20•(a+b)
b 123•5+123•1007+123•35789=123•(5+1007+35789) =123•36801= 4526523
c x•15+ו19-+ו23=x•(15+19+23)=x•57
d 43•×+a•43+43•b-m•43=43•(x+a+b - m)
e a•m-a•×+a•y=a•(m - x+y)
f 39•73+39•56+39•1256=39•(73+56+1256)=39•1385 = 54015
g 24•×-24-y-24•z+24•a=24•(x - y - z+a)
h 42•a-13•a-15•a-11•a=a•(42 - 13 - 15 - 11)=a•3