-123-{-123-[-123-(-123)]}
=-123-{-123-0}
=-123-(-123)
=0
\(=-123-\left(-123-\left(-123+123\right)\right)\)
\(=-123+123=0\)
-123-{-123-[-123-(-123)]}
=-123-{-123-0}
=-123-(-123)
=-123+123
=0
=-123-{-123-[-123+123]}
=-123-{-123+123-123}
=-123+123-123+123
=123+123+(-123)+123
=246