( - 2 + 4 - 3 ) × ( 7 - 5 + 8 - 2 - 7 ) = - 1
= ( 2 - 3 ) × ( 2 + 8 - 9 ) =
= ( - 1 ) × ( 10 - 9 ) =
= ( - 1) × 1 =
= - 1
(-2+4-3)•(7-5+8-2-7)=(2-3)•(2+8-2-7)=(-1)•(10-2-7)=(-1)•(8-7)=(-1)•1=-1
