[(320-3×13)+2-5×9+105×5]=
[(320-39)+2-5×9+105×5]=
(281+2-5×9+105×5)=
(281+2-45+525)=
283-45+525=
238+525=763
[320-(3×13+2)]-5×9+105×5=
[320-(39+2)]-5×9+105×5=
(320-41)-5×9+105×5=
279-5×9+105×5=
279-45+525=
234+525=759 Sper ca a fost bine ce ti-am scris!