regarding e way bill in case of works contract

Ankita Jain (Study and job) (110 Points)

23 January 2018  
Dear sir/madam,

1) when we issue invoice in case of works contract and sending some material for doing that work so how we quote item value in e way bill.
2) In case of this type of invoice both material and service elements is clubbed, we taking this service under gst as works contract & mention SAC. we cannot identify value of different material and even we identify the value of different material total of that material value don't match with invoice amt because it also has service element.

please reply
with regards
Ankita Jain