Question

-8+ {-5+[(8-12) + (13+12)] -10}

Answer 1

-8+{-5+[(8-12)+(13+12)]-10}
-8+{-5+[-4+25]-10}
-8+{-5+21-10}
-8+6
-2

Answer 2

-8 +{-5 +[(8-12) + (13-8+12)] -10}
-8+ {-5+[-4+25] -10}
-8+ {-5+ 21 -10}
-8+6
   -2