accounting for part exchange with vat

annefoth

can anyone help me please
having watched a you tube video by first intuition i am totally confused why the gross part exchange figure was debited to the cost account and not as i thought the net figure as there is vat to account for
although if the disposals is credited with the net figure and the vat account is credited with vat then the opposite account would have to be debited with the gross figure
also do we issue a sales invoice for a part exchange as if we accounted for the two transactions separately how would this be done
i would appreciate any help