Answer:

Then the constant terms of its factors have the same sign.

Suppose we have the trinomials:

x²+4x+4 and x²-5x+6

If we factor each of them, we will get:

x²+4x+4 = (x+2)(x+2)

x²-5x+6 = (x-2)(x-3)

Notice that in both sets of factors, the constant terms have the same sign---two positives (2 and 2) or both negative (-2 and -3).

So you will never forget, you use a mnemonic:

SAME SEX MARRIAGE FOR LGBT+