va rooooooooog va dau coroana

a) 47×67+53×67=3149+3551=6700
b) 453×250+750×453=113250+339750
c) 73×87+73×25-73×11=6351+1825-803=8176-803=7373
d) 83×26+24×83-45×50=2158+1992-2250=4150-2250=1900
e) 579+579×399-400×250=579+231021-100000=231600-100000=131600
f) 42+135×42-42×136=42+5670-5712=5712-5712=0

Obs. Voi folosii metoda gruparii si scoaterea in factor comun  !

a) 47*67+53*67=67*(47+53)=67*100=6700;
b) 453*250+750*453=453*(250+750)=453*1000=453000;
c) 73*87+73*25-73*11=73*(87+25-11)=73*101=7373;
d) 83*26+24*83-45*50=83*(26+24)-45*50=83*50-45*50=38*50=1900;
e) 579+579*399-400*250=579(1+399)-400*250=
                                        =579*400-400*250=400*329=131600;
f) 42+135*42-42*136=42*(1+135+136)=42*272=11424;