C1 : 78 . 31 + 78 . 24 + 78 . 17 + 22 . 72
= 78 ( 31 + 24 + 17 ) + 22 . 72
= 78 . 72 + 22 . 72
= ( 78 + 22 ) . 72
= 100 . 72
= 7200
C2 : 78 . 31 + 78 . 24 + 78 . 17 + 22 . 72
= 2418 + 1872 + 1326 + 1584
= 7200
\(78.31+78.24+78.17+22.72.\)
\(=78.\left(31+24+17\right)+22.72\)
\(=78.72+22.72\)
\(=72.\left(78+22\right)\)
\(=72.100=7200\)
C1:
78.31+78.24+78.17+22.72
= 78.(31+24+17)+22.72
= 78.72+22.72
= 72.(78+22)
=72.100
=7200
C2:
78.31+78.24+78.17+22.72
= 2418+78.24+78.17+22.72
= 2418+1872+78.17+22.72
= 2418+1872+1326+22.72
=2418+1872+1326+1584
= 4290+1326+1584
= 5616+1584
= 7200
\(78\times31+78\times24+78\times17+22\times72\)
\(=78\times\left(31+24+17\right)+22\times72\)
\(=78\times72+22\times72\)
\(=\left(78+22\right)\times72\)
\(=100\times72\)
\(=7200\)
_Chúc bạn học tốt_
\(78\cdot31+78\cdot24+78\cdot17+22\cdot72\)
\(=78\cdot\left(31+24+17\right)+28\cdot72\)
\(=78\cdot72+28\cdot72\)
\(=\left(72+28\right)\cdot72\)
\(=100\cdot72\)
\(=7200\)
78.31+78.24+78.17+22.72
=78(31+24+17)+22.72
=78.72+22.72
=72(78+22)
=72.100
=7200
k mik nha