Dilation is either : enlargement or shirking.
Simply you multiply the ordered pair times the dilation vector (Origin-Centered)
D.F = dilation factor;
d.f = 5
C' = d.fC
when you multiply a constant times an ordered pair , it multiples into each of the pair.
C' = 5 ( -5 , 1 ) = ( -25, 5 )
In case you were asked for A' , B' (test yourself before checking)
A' = 5 (-4,3) = ( -20 , 15)
B' = 5 ( 2, 3 ) = ( 10, 15)
Dividing the dilated by the original pair results in the dilation factor
A'/A = (-20/15)/(-4,3) = 5(-4,3)/(-4,3) = 5