Question

A triangle has vertices of (-2,-1),(0,-5) and (3,-2) What are the vertices of the image after applying the translation (x,y) (x+3,y-4)

Answer 1

I believe you meant (x,y) to (x+3, y-4).

In that case, you would add three to all of the x-coordinates and subtract four to all your y-coordinates. 

(-2,-1) is now (-2+3, -1-4). This is (1,-5).
(0,-5) is now (0+3, -5-4). This is (3,-9).
(3,-2) is now (3+3, -2-4). This is (6, -6).