3(2^2-6÷2)-15÷(2+2^4÷4-3^0)=
3(2^2-6÷2)-15÷(2+2^4÷4-3^0)=
3(2^2-6÷2)-15÷(2+2^4÷4-3^0)=
$3(4-3)-15÷(2+16÷4-1)=$
$3(1)-15÷(2+4-1)=$
$3-15÷5=$
$3-3=0$
3(2^2-6÷2)-15÷(2+2^4÷4-3^0)=
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$3(2^2-6~\colon2) -15~\colon(2+2^4~\colon4-3^0)$ =
= $3(4-3) -15~\colon(2+16~\colon4-1) $ =
= $3·1-15~\colon(2+4-1)$ =
= $3-15~\colon5$ =
= $3-3$ =
= $0$