\(53.39+47.39+53.21+47.21\)
\(=53\left(39+21\right)+47\left(39+21\right)\)
\(=53.60+47.60\)
\(=60\left(53+47\right)\)
\(=60.100\)
\(=6000.\)
Theo Thắng làm như sau : 53.39+47.39+53.21+47.2153.39+47.39+53.21+47.21
=53(39+21)+47(39+21)=53(39+21)+47(39+21)
=53.60+47.60=53.60+47.60
=60(53+47)=60(53+47)
=60.100=60.100
=6000.
53.39+47.39+53.21+47.21
= 39.(53+47)+21(53+47)
= (53+47)(39+21)
= 100.60
= 6000
53.39+47.39+53.21+47.21
= 39.( 53 + 47 ) + 21 . ( 53 + 47 )
= 39 . 100 + 21 . 100
= 3900 + 2100
= 6000
