Question

20+[(2x4-1)-5-8:4)+1]=

Answer 1

20+[(2*4-1-5-8/4)+1]=
20+[(8-1-5-2)+1]=
20+[0+1]=
20+1=
21

Answer 2

$Resolu\c{c}\~ao\to \left\{\begin{array}{ccc}20+[(2*4-1)-5-8:4)+1]=\\\\20+[(8-1)-5-2)+1]=\\\\20+[7-5-2+1]=\\\\20+1 =\\\\\boxed{= 21}\end{array}\right$

Espero ter ajudado. :))