Let us determine the product of 438 and 17 by partial products.
Consider
and
So,
=
= 7446
Therefore, the product of 438 and 17 is 7446.
No, Sandra's answer is not correct.
Because she should have expressed 17 as (10+7), then if she multiplied (438 by 10) and (438 by 7). And, then added the results.Then her answer would be correct.
The GCF is 4
The polynomial factors to
==========================================================
Further explanation:
Ignore the x terms
We're looking for the GCF of 12, 4 and 20
Factor each to their prime factorization. It might help to do a factor tree, but this is optional.
Each factorization involves "2*2", which means 2*2 = 4 is the GCF here.
We can then factor like so
The distributive property pulls out that common 4. We can verify this by distributing the 4 back in, so we get the original expression back again.
The polynomial inside the parenthesis cannot be factored further. Proof of this can be found by looking at the roots and noticing that they aren't rational numbers (use the quadratic formula).