Oracle Assets R12 direct join between FA_ADJUSTMENTS and FA_ASSET_INVOICES table using ASSET_INVOICE

Hi I am currently working on validating a fact table that has FA_ASSET_INVOICES and FA_ADJUSTMENTS

When I try to query both to verify the lines and dollars they are not balancing.

1.  query to join the two tables

select count(*), sum(adjustment_amount)

from   fa_adjustments a, fa_asset_invoices b

where    a.asset_invoice_id(+)=b.asset_invoice_id;

--count 954873

--adj amt 705084557.6

2, query for fa_asset_invoices only

select count(*), sum(fixed_assets_cost), sum(payables_cost), sum(payables_units)

from  fa_asset_invoices;

--872325

--assets_cost 1918087173.33 payables_cost 1821149767.52 payables_units 225358697

I would have expected the results to be the same but they are not.