See the 12 on the right end?
See the + sign before the 12?
See the 13 in the middle?
Think of two positive integers that when multiplied give 12,
but when ADDED (because the sign of 12 is +) gives 13.
We think of 12 and 1 because 12×1=12 and 12+1=13
S we write this
(x 12)(x 1)
Now since the sign of 12 is +, the signs will both be
the same. What sign? We look at the sign in the middle,
the sign of 13. It is +, so we put +'s in both parentheses:
(x+12)(x+1)
That's it.
We check by FOIL and get
x²+x+12x+12
which simplifies to:
x²+13x+12
So it checks.
Answer: (x+12)(x+1)
Edwin