Question

Folosind propietatile înmultiri , calculati cât mai simplu
a) 25×897×4;
c) 23×81+77×81;
d)672×47+672×53;
f) 93×67+93×89-93×56

Answer 1

25*897*4=22425*4=89700
23*81+77*81=1863+6237=8100
672*47+672*53=31584+35616=67200
93*67+93*89-93*56=6231+8277-5208=14508-5208=9300

Answer 2

a)  25*897*4 = (25*4)*897 = 100*897 = 89700 ;
c)  23*81+77*81 = 81*(23+77)=81*100=8100  ;
d)  672*47+672*53 = 672*(47+53)=672*100 = 67200 ;
f)  93*67+93*89-93*56 = 93*[(67+89)-56] = 93* [156-56] = 93*100 = 9300 ;