( 26 + 53 ) + ( 42 - 26 - 55 - 53 )
= ( 26 - 26 ) + ( 53 - 53 ) - 55 + 42 = 0 + 0 - 55 + 42 = - 13( 26 + 53 ) + ( 42 - 26 - 55 - 53 )
= ( 26 - 26 ) + ( 53 - 53 ) + 42 + 55
= 0 + 0 + 42 + 55
= 97
(26+53)+(42-26-55-53)
=(53-53)+(26-26)-55+42
=0+0-13
=-13