How is Jesus a descendant of David?

I need a concise explanation of the veracity of Jesus' lineage. Why is Jesus considered to be a true descendant of the House of David?

The genealogies of our Lord in Matthew 1 and Luke 3 state very clearly that Jesus’ human ancestry is traced to King David (Matthew 1: 6; Luke 3:31).  Because the two genealogies list different names in the generations from David to Joseph, it is generally believed that Matthew’s genealogy traces Joseph’s ancestry, while Luke’s genealogy traces Mary’s.

In addition, Luke 2:4 describes Joseph belonging “to the house and line of David.”  As Joseph was Jesus’ legal guardian/parent, Jesus is a legal descendant of David.

Of interest is the acclamation of the Palm Sunday crowds:  “Hosanna to the Son of David!”  (Matthew 21:9).  That was praise Jesus accepted because the title was accurate.