( - 2 ) + 4 + ( - 6 ) + 8 + ( - 10 ) + 12
= { ( - 2 ) + 4 } + { ( - 6 ) + 8 } + { ( - 10 ) + 12 }
= - 2 + - 2 + - 2
= ( - 2 ) . 3
= - 6
( - 2 ) + 4 + ( - 6 ) + 8 + ( - 10 ) + 12
= { ( - 2 ) + 4 } + { ( - 6 ) + 8 } + { ( - 10 ) + 12 }
= - 2 + - 2 + - 2
= ( - 2 ) . 3
= - 6