I need help finding the BP ages of :

Question

(when the present year is 1950)
Giant Sequoia tree rings from California. Date: 979 ± 52 years BCE

Cedar of Lebanon fragments from funeral boat of Egyptian King Sesostris III. Date: 1843 ± 50 years BC

and the BP dates of:
(assuming this is 1999)
Pleistocene mammoth bone from La Brea Tar Pits of Los Angeles, California. Age: 12,200 ± 35 years

Cottage roof timber from Ireland. Date: 906 ± 35 years

Answer 1

1950 - 979 = 971 BP

Calculate the others the same way.

Answer 2

oh sorry that one is BCE the first question

Answer 3

1950 + 979 = 2929

1950 + 1843 = 3793

Answer 4

Pleistocene mammoth bone from La Brea Tar Pits of Los Angeles, California. Age: 12,200 ± 35 years