Question

{[(-7+8)-(-8-2)+7-8+(9-10)]-40}

Answer 1

{[(-7+8)-(8-2)+7-8+(9-10)]-40} => {[1-6+7-8-1]-40} => {-7-40} => -47    

Answer 2

{[(-7+8)-(-8-2)+7-8+(9-10)]-40}
{[(+1)-(-10)+7-8+(-1)]-40}
{[+1+10+7-8-1]-40}
{[9]-40}
{9-40}
-31