+128472 5) 448n^4 - 56n^3 -56n^2 + 7n
Let's factor the last two terms, first = -7n ( 8n - 1)
Now ,RP..let's guess that (8n - 1) might factor the first two terms in some manner
So we have (8n - 1) and notice that if I multiply this by 56n^3 ... we have 56n^3 (8n -1) = 448n^4 - 56n^3
So...the factorization becomes
56n^3 (8n - 1) - 7n (8n - 1) =
(8n- 1) (56n^3 - 7n) and we can factor a 7n out of the second factor giving us
(8n - 1) * 7n * ( 8n^2 - 1) =
7n (8n - 1) (8n^2 - 1)
6) 45a^5 + 54a^4 - 60a^3 - 72a^2
GCF 45a^5 and 54a^4 = 9a^4
GCF -60a^3 and - 72a^2 = -12a^2
So we have
9a^4 ( 5a + 6) - 12a^2 (5a + 6)
(5a + 6) (9a^4 - 12a^2)....we can factor 3a^2 out of the second factor
(5a + 6) * 3a^2 * ( 3a^2 - 4) =
3a^2 (5a + 6) (3a^2 - 4)
