The fractional part would be 4/5 because 2000-1600=400 and if you divide 2000 by 400 and 1600 by 400 you get 4/5 (wrong order when solving, srry). Hope that helped :D
Expand by multiplying x2+4x-4 by multiplying by x+4. Distribute and get x3+8x2+12x-16. You can verify it is correct by dividing by x+4 and you will arrive at x2+4x-4.
