Question

1+{-2+[3+(-4+5-6)+7]-8}

Answer 1

$1+[-2+[3+(-4+5-6)+7]-8]$

$1+[-2+[3+(1-6)+7]-8]$

$1+[-2+[3+(-5)+7]-8]$

$1+[-2+[3-5+7]-8]$

$1+[-2+[-2+7]-8]$

$1+[-2+5-8]$

$1+[3-8]$

$1+[-5]$

$1-5$

$-4$