Resposta:

{[(8.4+3)÷7+(3+15÷5).3].2-(19-7)÷6}.2+12=
{[(24+3)÷7+(3+3).3].2-(19-7)÷6}.2+12=
{[(27)÷7+(6).3].2-(12)÷6}.2+12=
{[3.85+6.3].2-12÷6}.2+12=
{[3.85+18].2-12÷6}.2+12=
{[21.85].2-12÷6}.2+12=
{21.85.2-12÷6}.2+12=
{43.7-12÷6}.2+12=
{31.7÷6}.2+12=
5.28.2+12=
10.56+12=
=22.56

Explicação passo a passo:tentei irmao se tiver errado me desculpe