Originally Posted by

**kappa** If you ask me to simplify (x+3)(x+5), I'd do it easily by multiplying both sides.

(x+3)(x+5)=

x*x+5x+3x+3*5=

x2+8x+15

But if you ask:

Explain: x2+8x+15 = (x+3)(x+5)

I'd be dumbfounded.

How do I "see" that it is so more logically other than remembering what a simple polynomial multiplication looks like? help on this is MUCH required as I'll be tested both ways, I will definitely fail if I can't wrap my head around this one. PLEASE help me see it! Thanks in advance, any thought-provoking comments appreciated.