Can someone please help me its urgent I don’t get this

1. what are the missing reasons in the proof 2. it's in the second picture and 3

Which value of c would make he following expression completely factored? 8x+cy

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)