Answer
$20, -12$
Work Step by Step
With the FOIL method, with m and n being integers, we find that
$(x+m)(x+n)=x^{2}+(m+n)x+ mn,$
so ,the sum of m and n is the coefficient of x, and
m and n are factors of the constant term.
Reversing, when we want to factor $x^{2}+bx+c,$ we search for two integers, m and n such that
their sum is b,
their product is c.
Here, $x^{2}-12x+20,\qquad (b=-12, c=20)$,
the product of m and n should be 20,
the sum: $-12.$