{10+5+3.[18-15+(20-15).4]-8.8}:5-2+3=
{10+5+3.[18-15+(20-15).4]-8.8}:5-2+3=
{10+5+3.[18-15+(20-15).4]-8.8} : 5-2+3=
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Sperando di interpretare bene, visto come hai usato il punto per moltiplicare:
$\{10+5+3·[18-15+(20-15)·4]-8·8\} : 5-2+3=$
$=\{15+3·[3+5·4]-64\} : 5+1=$
$=\{15+3·[3+20]-64\} : 5+1=$
$=\{15+3·23-64\} : 5+1=$
$=\{15+69-64\} : 5+1=$
$=20 : 5+1=$
$=4+1=$
$=5$
{10+5+3.[18-15+(20-15).4]-8.8}:5-2+3
{15+3*[3+5*4]-8*8}:5 +1
{15+3*23-64}:5+1
(84-64):5+1
20:5+1
4+1 = 5