Question

18-(14+15)-[13-(16-21)]

Answer 1

18-(14+15)-[13-(16-21)]
18 - (14 + 15) - [13 - (-5)]
18 - (14 + 15) - [13 + 5]
18 - (14 + 15) - 18
18 - 29 - 18
- 29 

Answer 2

$18-(14+15)-[13-(16-21)]$


$18-(29)-[13-(-5)]$


$18-29-[13+5]$


$18-29-18$


$\boxed {-29}$