Please help and explain this to me

An advertising firm has an old computer that can prepare a whole mailing in 6 hours. with the of newer model the job is complete in 2 hours. how long would it take the newer model to do the job alone?

An object is translated by (x + 4, y - 2). if one point in the image has the coordinates (5, -3), what would be the coordinates of its pre-image? (9, -5) (1, -5) (9, -1) (1, -1)

Using elimination, what is -4x+2y=-12 4x+8y=-24