Answer:
17) C
18) D
19) B
Explanation:
17) As you see that is a fraction ahead of x^2. So you stretch it vertically. The best part here is even if you forget the principle just search for transformations of relative function (by relative I mean the function from context).
18) (x-2)^2 - 1, the -1 translates the graph down on a unit.
the horizontal transformation is defined as (x - a) or in other words, if you see -2 you actually move the graph on 2 units.
19) You see that -1/3 which means you reflect it over the y-axis and compress it by a factor of 3. Also, we translate it to the right by 3.
Do the 20th yourself now.