How do you factor #9-72m+144m^2#?
1 Answer
May 20, 2017
Explanation:
Note that all of the coefficients are divisible by
#9-72m+144m^2 = 9(16m^2-8m+1)#
#color(white)(9-72m+144m^2) = 9((4m)^2-2(4m)+1)#
#color(white)(9-72m+144m^2) = 9(4m-1)^2#
Footnote
If you know your square numbers, then you might recognise:
#1681 = 41^2#
like:
#16m^2-8m+1 = (4m-1)^2#
This is no coincidence.
When you square