b)={[(2+6)*2-4]\3+5}*2-5=[(8*2-4)\3+5]*2-5=[(16-4)\3+5]*2-5=(12\3+5)*2-5=(4+5)*2-5=9*2-5=18-5=13 a)[680\20+4*(2+12\12)]*100=[34+4*(2+1)]*100=(34+4*3)*100=(34+12)*100=46*100=4600 c)=9+10*{9+10*[9+10*(9+90)-9]-9}-9=9+10*[9+10*(9+10*99-9)-9]-9=9+10*[9+10*(9+990-9)-9]-9=9+10*(9+10*990-9)-9=9+108(9+9900-9)-9=9+10*9900-9=9+99000-9=99009-9=99000
