How do you factor 20m^2+13mn+2n^2?

1 Answer
Jun 3, 2015

20m^2+13mn+2n^2 is homogeneous in that all of the terms are of degree 2, so it can be factored like 20x^2+13x+2,

Use AC Method to factor.

A=20, B=13, C=2

Look for a factorization of AC=20*2=40 into a pair of factors whose sum is B=13.

The pair B1=5, B2=8 works.

Then for each of the pairs (A, B1) and (A, B2), divide that pair by the HCF (highest common factor) to get the coefficients of a factor...

(A, B1) = (20, 5), HCF=5 -> (4, 1) -> (4m+n)
(A, B2) = (20, 8), HCF=4 -> (5, 2) -> (5m+2n)

So 20m^2+13mn+2n^2 = (4m+n)(5m+2)