Problem returning result

Hello,
I have this query:

select e.quantity, rl.quantity
from logistics_inout.reception r
left join logistics_inout.reception_line rl on
rl.reception_id = r.id
left join logistics_inout.reception_documents rd on
r.id = rd.reception_id
left join logistics_inout.document_line e on
rd.documents_id = e.document_id
where rl.reception_id = 5738
and rl.product_id = 20992
and e.product_id = 20992

the result is:

quantity quantity_1
16.00 1.00
4.00 1.00
16.00 1.00
4.00 1.00
16.00 1.00
4.00 1.00
16.00 1.00
4.00 1.00
16.00 1.00
4.00 1.00
16.00 1.00
4.00 1.00
16.00 1.00
4.00 1.00
16.00 1.00
4.00 1.00
16.00 1.00
4.00 1.00
16.00 1.00
4.00 1.00
16.00 1.00
4.00 1.00
16.00 1.00
4.00 1.00
16.00 1.00
4.00 1.00
16.00 1.00
4.00 1.00
16.00 1.00
4.00 1.00
16.00 1.00
4.00 1.00
16.00 1.00
4.00 1.00
16.00 1.00
4.00 1.00
16.00 1.00
4.00 1.00
16.00 1.00
4.00 1.00
16.00 1.00
4.00 1.00


And it should be:
20 21

The product code is just for testing the result, when it all goes well with the query i will remove it
Please help me

Thank you