Question

{-5+2{5-7+2{10-7-5}+2}-4}

Answer 1

espero q sea asi :
{-5+2{5-7+2{10-7-5}+2}-4}
={-5+2{5-7+20-14-10}-4}
={-5+10-14+40-28-30-4}
= -5+10-14+40-28-30-4
= -81 +50
=-31

Answer 2

{-5+2{5-7+20-14-10+2}-4} 
{-5+10-14+40-28-20+4-4}
-5+10-14+40-28-20
-71+30= -41

R= - 41