Sorry, I did not see this till today.
When Abe's dad (Terah) died in Haran, Abe left Haran.
We know how old Terah was when he died in Haran, cause scripture outright tells us.
Gen 11:32 And the days of Terah were two hundred and five years: and Terah died in Haran.
205 (Age of Terah when he died in Haran.)
And we know how old Abe was when he left Haran after Terah died, cause scripture tells us.
Actc 7
3 And said unto him, Get thee out of thy country, and from thy kindred, and come into the land which I shall show thee.
4 Then came he out of the land of the Chaldeans, and dwelt in Haran: and from thence, when his father was dead, he removed him into this land, wherein ye now dwell.
Gen 12:4 So Abram departed, as the LORD had spoken unto him; and Lot went with him: and Abram [was] seventy and five years old when he departed out of Haran.
75 (Age of Abraham when his father died and he left Haran.)
205-
75=130
Terah was 130 when Abe was born.
But we know from scripture that Terah began having children at age 70, so Abe could not have been his firstborn.
Gen 11:26 And Terah lived seventy years, and begat Abram, Nahor, and Haran.