(a) scale factor = 11, x = 33
(b) scale factor = 1/8, x = 7
the value you get for x in question (a) is correct. the scale factor is not quite right.
a scale factor answers the question of "what do i have to do to the first figure to get to the second one"?
so for (a) you start out with 10 in the first figure and get to 110 in the second one.
scale factor = second figure / first figure = 110/10 = 11
so your scale factor should be 11.
the next thing you do is
size of second figure = scale factor * size of first figure.
size of second figure = 11 * 3 = 33 which you already had.
scale factor = second figure / first figure = 6/48 = 1/8
x = scale factor * size of second figure.
x = 1/8 * 56 = 7
the problem does not change in method if you have to go from the second figure to the first, but you have to be careful how you set it up.