drop table sales;
create table sales (
	part_no	varchar2(10),
	col_out		number(14,4)
);

	
insert into sales values ( 'AC4505', -420.5887 );
insert into sales values ( 'AC4506', -248.484 );
insert into sales values ( 'AC4507', -14610.17 );
commit;

	

	
drop table income;
create table income (
	part_no	varchar2(10),
	col_in			number(14,4)
);

	
insert into income values ( 'AC4505', 400.6485 );
insert into income values ( 'AC4506', 202.322 );
insert into income values ( 'AC4507', 17461 );
commit;

	

	
create table result as
	select part_no, sum(result) result from
		(
		select part_no, col_out result from sales
		union all
		select part_no, col_in result from income
		)
	group by part_no;