a ) ( 13 - 145 + 49 ) - ( 13 + 49 )
= 13 - 145 + 49 - 13 - 49
= ( 13 - 13 ) - 145 + ( 49 - 49 )
= 0 - 145 + 0
= - 145
b) 25 . 22 . ( 15 - 18 ) + ( 12 - 19 + 10 )
= 25 . 4 . ( -3 ) + 7
= 100 . [ ( -3 ) + 7 ]
= 100 . 4
= 400
a ) ( 13 - 145 + 49 ) - ( 13 + 49 )
= 13 - 145 + 49 - 13 - 49
= ( 13 - 13 ) - 145 + ( 49 - 49 )
= 0 - 145 + 0
= - 145
( 13 - 145 + 49 ) - ( 13 + 49 )
= 13 - 145 + 49 - 13 - 49
= 13 - 13 + 49 - 49 - 145
= 0 + 0 - 145
= - 145
( 13 - 145 + 49 ) - ( 13 + 49 )
= 13 - 145 + 49 - 13 - 49
= 13 - 13 + 49 - 49 - 145
= 0 + 0 - 145
= - 145
a) ( 13 - 145 + 49 ) - ( 13 + 49 )
= 13 - 145 + 49 - 13 - 49
= 13 + ( - 145 ) + 49 + ( - 13 ) + ( - 49 )
= [ 13 + ( - 13 ) ] + [ 49 + ( - 49 ) ] + ( - 145 )
= 0 + 0 + ( - 145 )
= - 145
b) 25 . 22 ( 15 - 18 ) + ( 12 - 19 + 10 )
= 25 . 4.( - 3 ) + 3
= 100 . ( - 3 ) + 3
= - 300 + 3
= - 297