441 is odd, so we can't divide it by 2.
Since the sum of its digits is
, which is divisible by 3, we can divide 441 by 3, and we have

Which is still divisible by 3, because
. We have

49 is not divisible by 3 anymore, nor by 5 (it doesn't end with 0 or 5).
It is divisible by 7 though, we have

and finally,

So, the factorization of 441 is

Answer: The answer is P'(7, 17.5) and Q'(7, 3.5).
Step-by-step explanation: Given that a line segment PQ is dilated with a scale factor of 3.5 where origin is the centre of dilation.
The end points of segment PQ are P(2, 5) and Q(2, 1).
Therefore, after dilation, the coordinates of the end points become
Thus, the coordinates of P' are (7, 17.5) and the co-ordinates of Q' are (7, 3.5).