Factor as far as possible 3u^4-4u^3 and 3u^7+12u^2
for the first one you can say:u^3(3u - 4) and that's the answer because 3 is the biggest power that you can factor.for the second one also you can say:3u^2(u^5-4) and that's the answer. :)))I hope this is helpfulhave a nice day