b= [11,2(3)-9,(2)]·9-_1_
100
b= ( _1123 - 112_ - _92 - 9_ )·9 - _1_
90 9 100
b= ( _1 011_ - _83_ )·9 - _1_
90 9 100
b=( _1 011_ - _830_ )·9 - _1_
90 100
b=( _181_ )·9 - _1_
90 100
b= _181_ - _1_
10 100
b= _1 810 - 1_
100
b= _1 809_
100
b= 18, 09
c=(4,56+16,23-2,39):8
c= (20,79 - 2, 39) : 8
c= 18,40: 8
c= 2,30
c= 2,3