Ta có : ( 217 + 153 ) . ( 345 - 65 ) . ( 24 - 42 )
= ( 217 + 153 ) . ( 345 - 65 ) . (16 - 16)
= ( 217 + 153 ) . ( 345 - 65 ) . 0 = 0
(217 + 153) . (345 - 65) . (24 - 42)
= (217 + 153) . (345 - 65) . (16 - 16)
= (217 + 153) . (345 - 65) . 0
= 0
= ( 217 + 153 ) . ( 345 - 65 ) . ( 16 - 16 )
= ( 217 + 153 ) . ( 345 - 65 ) . 0
= 0