Question

[  123 x345 ] x [ 13 x15 - 12 x15 -15 ]

Answer 1

( 123 x 345 ) x ( 13 x 15 - 12 x 15 - 15 )

= ( 123 x 345 ) x ( 13 x 15 - 12 x 15 - 15 x 1 )

= ( 123 x 345 ) x ( (13 - 12 -1 ) x 15 )

= ( 123 x 345 ) x ( 0 x 15 )

= ( 123 x 345 ) x 0

= 0