Question

|-13|+|26|-|-18|+|-12|

Answer 1

Ah, let me help you on this one.

These weird lines (|) are actually indicators of absolute value.

All of the negative numbers will be transformed into non-negative ones.

Neat, huh?

13+26-18+12 equals to 33



P.S. If this answer helped you, please, make sure to say "Thanks" just below my answer. It will help me a lot.

Answer 2

33
The lines stand for absolute value. The expression would then look like:
13+26-18+12
39-18+12
21+12
33