Question 439409
c) 108y-4y^4
The common factors here are 4 and y
therefore take these two terms outside the brackets as seen below:
4y(27 - y^3)

Note:
108y/4y = 27 and 4y^4/4y = y^3

d) 63m^3n^2 - 7mn^4
look for the terms that are common to both numbers
in this case, it is 7mn^2
so:
7mn^2(9m^2 - n^2)