108*(23+7)=180*30=5400
215*86+215*14=215*(86+14)=215*100=21500
53*128-43*128=128*(53-43)=128*10=1280
mk đúng nha
108 x ( 23 + 7 )
= 108 x 30
= 3240
215 x 86 + 215 x 14
= 215 x ( 86 + 14 )
= 216 x 100
= 21600
53 x 128 - 43 x 128
= ( 53 - 43 ) x 128
= 10 x 128
=1280
1: 108 x (23+7) 215 x 86 +215x14 53x128 -43x128
=108x 30 =215x(86+14) =(53-43) x128
=3240 =215x100=21500 =10x128=1280