Răspuns:
58(45+26)=58×71=4118 sau 58(45+26)=58×45+58×26=2610+1508=4118
(78-39)×25=39×25=975 sau (78-39)×25=78×25-39×25=1950-975=975
(75+15)×40=90×40=3600 sau (75+15)×40=75×40+15×40=3000+600=3600
72×(100-55)=72×45=3240 sau 72×(100-55)=72×100-72×55=7200-3960=3240
cu plăcere :))
