USA test prep please answer

In triangle abc, the length of side ab is 12 cm, the length of side bc is 5 cm, and the length of side ca is 9 cm. find the measure of angle a using the law of cosines.

Quadrilateral ghjk has vertices g(2, 3), h(8, 2), j(6, 8), and k(3, 6). it is transformed according to the rule t(–4, –5). what are the coordinates of g”? (–7, 3) (–2, 2) (–1, –7) (2, –2)

Aboat costs 19200 and decreases in value by 12% per year. how much will it cost in 5 years