Question

{20+[80-50-(23-3+8)+(12+5)]}=

Answer 1

{20+[80-50-(23-3+8)+(12+5)]}=
{20+[80-50-(28)+(17)]}=
{20+[30-(28)+(17)]}=
{20+[30-28+17]}=
{20+[19]}=
20+19=
39