a)
a=2,4:12+9,8
a=0,2+9,8
a=10
[tex]b=(11 \frac{21}{90} -9 \frac{2}{9} )*9-0,1;b=( \frac{1011}{90} - \frac{83}{9} )*9-0,1[/tex]
[tex]b= \frac{(1011-830)}{90} *9-0,1;b= \frac{181}{90} *9-0,1;b= \frac{181}{10} - \frac{1}{10} ;b= \frac{180}{10} ;b=18[/tex]
b)
(3+20+36)/3=59/3=19intregi2/3